Index: lemon/Makefile.am
===================================================================
--- lemon/Makefile.am	(revision 2229)
+++ lemon/Makefile.am	(revision 2260)
@@ -122,10 +122,10 @@
 concept_HEADERS += \
 	lemon/concept_check.h \
-	lemon/concept/bpugraph.h \
-	lemon/concept/graph.h \
-	lemon/concept/graph_components.h \
-	lemon/concept/heap.h \
-	lemon/concept/maps.h \
-	lemon/concept/matrix_maps.h \
-	lemon/concept/path.h \
-	lemon/concept/ugraph.h
+	lemon/concepts/bpugraph.h \
+	lemon/concepts/graph.h \
+	lemon/concepts/graph_components.h \
+	lemon/concepts/heap.h \
+	lemon/concepts/maps.h \
+	lemon/concepts/matrix_maps.h \
+	lemon/concepts/path.h \
+	lemon/concepts/ugraph.h
Index: lemon/bellman_ford.h
===================================================================
--- lemon/bellman_ford.h	(revision 2151)
+++ lemon/bellman_ford.h	(revision 2260)
@@ -93,5 +93,5 @@
     ///
     /// The type of the map that stores the edge lengths.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _LengthMap LengthMap;
 
@@ -111,5 +111,5 @@
     /// The type of the map that stores the last
     /// edges of the shortest paths.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename _Graph::Edge> PredMap;
@@ -126,5 +126,5 @@
     ///
     /// The type of the map that stores the dists of the nodes.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename _LengthMap::Value> 
@@ -147,5 +147,5 @@
   /// This class provides an efficient implementation of \c Bellman-Ford 
   /// algorithm. The edge lengths are passed to the algorithm using a
-  /// \ref concept::ReadMap "ReadMap", so it is easy to change it to any 
+  /// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any 
   /// kind of length.
   ///
@@ -159,5 +159,5 @@
   ///
   /// The type of the length is determined by the
-  /// \ref concept::ReadMap::Value "Value" of the length map.
+  /// \ref concepts::ReadMap::Value "Value" of the length map.
   ///
   /// \param _Graph The graph type the algorithm runs on. The default value
@@ -165,5 +165,5 @@
   /// BellmanFord, it is only passed to \ref BellmanFordDefaultTraits.
   /// \param _LengthMap This read-only EdgeMap determines the lengths of the
-  /// edges. The default map type is \ref concept::Graph::EdgeMap 
+  /// edges. The default map type is \ref concepts::Graph::EdgeMap 
   /// "Graph::EdgeMap<int>".  The value of _LengthMap is not used directly 
   /// by BellmanFord, it is only passed to \ref BellmanFordDefaultTraits.  
@@ -791,5 +791,5 @@
     ///
     /// The type of the map that stores the edge lengths.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _LengthMap LengthMap;
 
@@ -809,5 +809,5 @@
     /// The type of the map that stores the last
     /// edges of the shortest paths.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     typedef NullMap <typename _Graph::Node,typename _Graph::Edge> PredMap;
 
@@ -821,5 +821,5 @@
     ///
     /// The type of the map that stores the dists of the nodes.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     typedef NullMap<typename Graph::Node, Value> DistMap;
     /// \brief Instantiates a DistMap.
Index: lemon/bfs.h
===================================================================
--- lemon/bfs.h	(revision 2151)
+++ lemon/bfs.h	(revision 2260)
@@ -48,5 +48,5 @@
     ///The type of the map that stores the last
     ///edges of the shortest paths.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename GR::Edge> PredMap;
@@ -63,5 +63,5 @@
  
     ///The type of the map that indicates which nodes are processed.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///\todo named parameter to set this type, function to read and write.
     typedef NullMap<typename Graph::Node,bool> ProcessedMap;
@@ -82,5 +82,5 @@
  
     ///The type of the map that indicates which nodes are reached.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///\todo named parameter to set this type, function to read and write.
     typedef typename Graph::template NodeMap<bool> ReachedMap;
@@ -97,5 +97,5 @@
  
     ///The type of the map that stores the dists of the nodes.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<int> DistMap;
@@ -706,5 +706,5 @@
     ///The type of the map that stores the last
     ///edges of the shortest paths.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef NullMap<typename Graph::Node,typename GR::Edge> PredMap;
@@ -726,5 +726,5 @@
  
     ///The type of the map that indicates which nodes are processed.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///\todo named parameter to set this type, function to read and write.
     typedef NullMap<typename Graph::Node,bool> ProcessedMap;
@@ -745,5 +745,5 @@
  
     ///The type of the map that indicates which nodes are reached.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///\todo named parameter to set this type, function to read and write.
     typedef typename Graph::template NodeMap<bool> ReachedMap;
@@ -760,5 +760,5 @@
  
     ///The type of the map that stores the dists of the nodes.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef NullMap<typename Graph::Node,int> DistMap;
Index: lemon/bits/array_map.h
===================================================================
--- lemon/bits/array_map.h	(revision 2202)
+++ lemon/bits/array_map.h	(revision 2260)
@@ -25,5 +25,5 @@
 #include <lemon/bits/alteration_notifier.h>
 #include <lemon/concept_check.h>
-#include <lemon/concept/maps.h>
+#include <lemon/concepts/maps.h>
 
 /// \ingroup graphbits
@@ -142,5 +142,5 @@
     template <typename CMap>
     ArrayMap& operator=(const CMap& cmap) {
-      checkConcept<concept::ReadMap<Key, _Value>, CMap>();
+      checkConcept<concepts::ReadMap<Key, _Value>, CMap>();
       const typename Parent::Notifier* notifier = Parent::getNotifier();
       Item it;
Index: lemon/bits/base_extender.h
===================================================================
--- lemon/bits/base_extender.h	(revision 2231)
+++ lemon/bits/base_extender.h	(revision 2260)
@@ -27,5 +27,5 @@
 
 #include <lemon/concept_check.h>
-#include <lemon/concept/maps.h>
+#include <lemon/concepts/maps.h>
 
 ///\ingroup graphbits
Index: lemon/bits/debug_map.h
===================================================================
--- lemon/bits/debug_map.h	(revision 2202)
+++ lemon/bits/debug_map.h	(revision 2260)
@@ -30,5 +30,5 @@
 
 #include <lemon/concept_check.h>
-#include <lemon/concept/maps.h>
+#include <lemon/concepts/maps.h>
 
 ///\ingroup graphbits
@@ -187,5 +187,5 @@
     template <typename CMap>
     DebugMap& operator=(const CMap& cmap) {
-      checkConcept<concept::ReadMap<Key, _Value>, CMap>();
+      checkConcept<concepts::ReadMap<Key, _Value>, CMap>();
       const typename Parent::Notifier* notifier = Parent::getNotifier();
       Item it;
Index: lemon/bits/graph_extender.h
===================================================================
--- lemon/bits/graph_extender.h	(revision 2231)
+++ lemon/bits/graph_extender.h	(revision 2260)
@@ -27,5 +27,5 @@
 
 #include <lemon/concept_check.h>
-#include <lemon/concept/maps.h>
+#include <lemon/concepts/maps.h>
 
 ///\ingroup graphbits
@@ -1129,5 +1129,5 @@
       template <typename CMap>
       NodeMap& operator=(const CMap& cmap) {
-	checkConcept<concept::ReadMap<Node, _Value>, CMap>();
+	checkConcept<concepts::ReadMap<Node, _Value>, CMap>();
         aNodeMap = cmap;
         bNodeMap = cmap;
Index: lemon/bits/map_extender.h
===================================================================
--- lemon/bits/map_extender.h	(revision 2031)
+++ lemon/bits/map_extender.h	(revision 2260)
@@ -25,5 +25,5 @@
 
 #include <lemon/concept_check.h>
-#include <lemon/concept/maps.h>
+#include <lemon/concepts/maps.h>
 
 ///\file
@@ -207,5 +207,5 @@
     template <typename CMap>
     SubMapExtender& operator=(const CMap& cmap) {
-      checkConcept<concept::ReadMap<Key, Value>, CMap>();
+      checkConcept<concepts::ReadMap<Key, Value>, CMap>();
       Item it;
       for (graph.first(it); it != INVALID; graph.next(it)) {
Index: lemon/bits/vector_map.h
===================================================================
--- lemon/bits/vector_map.h	(revision 2202)
+++ lemon/bits/vector_map.h	(revision 2260)
@@ -29,5 +29,5 @@
 
 #include <lemon/concept_check.h>
-#include <lemon/concept/maps.h>
+#include <lemon/concepts/maps.h>
 
 ///\ingroup graphbits
@@ -134,5 +134,5 @@
     template <typename CMap>
     VectorMap& operator=(const CMap& cmap) {
-      checkConcept<concept::ReadMap<Key, _Value>, CMap>();
+      checkConcept<concepts::ReadMap<Key, _Value>, CMap>();
       const typename Parent::Notifier* notifier = Parent::getNotifier();
       Item it;
Index: lemon/color.h
===================================================================
--- lemon/color.h	(revision 2230)
+++ lemon/color.h	(revision 2260)
@@ -101,5 +101,5 @@
 ///number. The integer range is cyclically mapped to the provided set of colors.
 ///
-///This is a true \ref concept::ReferenceMap "reference map", so you can also
+///This is a true \ref concepts::ReferenceMap "reference map", so you can also
 ///change the actual colors.
 
Index: lemon/concept/bpugraph.h
===================================================================
--- lemon/concept/bpugraph.h	(revision 2231)
+++ 	(revision )
@@ -1,1020 +1,0 @@
-/* -*- C++ -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library
- *
- * Copyright (C) 2003-2006
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-/// \ingroup graph_concepts
-/// \file
-/// \brief Undirected bipartite graphs and components of.
-
-
-#ifndef LEMON_CONCEPT_BPUGRAPH_H
-#define LEMON_CONCEPT_BPUGRAPH_H
-
-#include <lemon/concept/graph_components.h>
-
-#include <lemon/concept/graph.h>
-#include <lemon/concept/ugraph.h>
-
-#include <lemon/bits/utility.h>
-
-namespace lemon {
-  namespace concept {
-
-    /// \addtogroup graph_concepts
-    /// @{
-
-
-    /// \brief Class describing the concept of Bipartite Undirected Graphs.
-    ///
-    /// This class describes the common interface of all 
-    /// Undirected Bipartite Graphs.
-    ///
-    /// As all concept describing classes it provides only interface
-    /// without any sensible implementation. So any algorithm for
-    /// bipartite undirected graph should compile with this class, but it 
-    /// will not run properly, of course.
-    ///
-    /// In LEMON bipartite undirected graphs also fulfill the concept of 
-    /// the undirected graphs (\ref lemon::concept::UGraph "UGraph Concept"). 
-    ///
-    /// You can assume that all undirected bipartite graph can be handled
-    /// as an undirected graph and consequently as a static graph.
-    ///
-    /// The bipartite graph stores two types of nodes which are named
-    /// ANode and BNode. The graph type contains two types ANode and
-    /// BNode which are inherited from Node type. Moreover they have
-    /// constructor which converts Node to either ANode or BNode when
-    /// it is possible. Therefor everywhere the Node type can be used
-    /// instead of ANode and BNode. So the usage of the ANode and
-    /// BNode is not suggested.
-    ///
-    /// The iteration on the partition can be done with the ANodeIt and 
-    /// BNodeIt classes. The node map can be used to map values to the nodes
-    /// and similarly we can use to map values for just the ANodes and
-    /// BNodes the ANodeMap and BNodeMap template classes.
-
-    class BpUGraph {
-    public:
-      /// \brief The undirected graph should be tagged by the
-      /// UndirectedTag.
-      ///
-      /// The undirected graph should be tagged by the UndirectedTag. This
-      /// tag helps the enable_if technics to make compile time 
-      /// specializations for undirected graphs.  
-      typedef True UndirectedTag;
-
-      /// \brief The base type of node iterators, 
-      /// or in other words, the trivial node iterator.
-      ///
-      /// This is the base type of each node iterator,
-      /// thus each kind of node iterator converts to this.
-      /// More precisely each kind of node iterator should be inherited 
-      /// from the trivial node iterator. The Node class represents
-      /// both of two types of nodes. 
-      class Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        Node() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        Node(const Node&) { }
-
-        /// Invalid constructor \& conversion.
-
-        /// This constructor initializes the iterator to be invalid.
-        /// \sa Invalid for more details.
-        Node(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(Node) const { return true; }
-
-        /// Inequality operator
-        
-        /// \sa operator==(Node n)
-        ///
-        bool operator!=(Node) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(Node) const { return false; }
-
-      };
-
-      /// \brief Helper class for ANodes.
-      ///
-      /// This class is just a helper class for ANodes, it is not
-      /// suggested to use it directly. It can be converted easily to
-      /// node and vice versa. The usage of this class is limited
-      /// to use just as template parameters for special map types. 
-      class ANode : public Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        ANode() : Node() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        ANode(const ANode&) : Node() { }
-
-        /// Construct the same node as ANode.
-
-        /// Construct the same node as ANode. It may throws assertion
-        /// when the given node is from the BNode set.
-        ANode(const Node&) : Node() { }
-
-        /// Assign node to A-node.
-
-        /// Besides the core graph item functionality each node should
-        /// be convertible to the represented A-node if it is it possible. 
-        ANode& operator=(const Node&) { return *this; }
-
-        /// Invalid constructor \& conversion.
-
-        /// This constructor initializes the iterator to be invalid.
-        /// \sa Invalid for more details.
-        ANode(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(ANode) const { return true; }
-
-        /// Inequality operator
-        
-        /// \sa operator==(ANode n)
-        ///
-        bool operator!=(ANode) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(ANode) const { return false; }
-
-      };
-
-      /// \brief Helper class for BNodes.
-      ///
-      /// This class is just a helper class for BNodes, it is not
-      /// suggested to use it directly. It can be converted easily to
-      /// node and vice versa. The usage of this class is limited
-      /// to use just as template parameters for special map types. 
-      class BNode : public Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        BNode() : Node() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        BNode(const BNode&) : Node() { }
-
-        /// Construct the same node as BNode.
-
-        /// Construct the same node as BNode. It may throws assertion
-        /// when the given node is from the ANode set.
-        BNode(const Node&) : Node() { }
-
-        /// Assign node to B-node.
-
-        /// Besides the core graph item functionality each node should
-        /// be convertible to the represented B-node if it is it possible. 
-        BNode& operator=(const Node&) { return *this; }
-
-        /// Invalid constructor \& conversion.
-
-        /// This constructor initializes the iterator to be invalid.
-        /// \sa Invalid for more details.
-        BNode(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(BNode) const { return true; }
-
-        /// Inequality operator
-        
-        /// \sa operator==(BNode n)
-        ///
-        bool operator!=(BNode) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(BNode) const { return false; }
-
-      };
-    
-      /// This iterator goes through each node.
-
-      /// This iterator goes through each node.
-      /// Its usage is quite simple, for example you can count the number
-      /// of nodes in graph \c g of type \c Graph like this:
-      ///\code
-      /// int count=0;
-      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
-      ///\endcode
-      class NodeIt : public Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        NodeIt() { }
-        /// Copy constructor.
-        
-        /// Copy constructor.
-        ///
-        NodeIt(const NodeIt& n) : Node(n) { }
-        /// Invalid constructor \& conversion.
-
-        /// Initialize the iterator to be invalid.
-        /// \sa Invalid for more details.
-        NodeIt(Invalid) { }
-        /// Sets the iterator to the first node.
-
-        /// Sets the iterator to the first node of \c g.
-        ///
-        NodeIt(const BpUGraph&) { }
-        /// Node -> NodeIt conversion.
-
-        /// Sets the iterator to the node of \c the graph pointed by 
-	/// the trivial iterator.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        NodeIt(const BpUGraph&, const Node&) { }
-        /// Next node.
-
-        /// Assign the iterator to the next node.
-        ///
-        NodeIt& operator++() { return *this; }
-      };
-
-      /// This iterator goes through each ANode.
-
-      /// This iterator goes through each ANode.
-      /// Its usage is quite simple, for example you can count the number
-      /// of nodes in graph \c g of type \c Graph like this:
-      ///\code
-      /// int count=0;
-      /// for (Graph::ANodeIt n(g); n!=INVALID; ++n) ++count;
-      ///\endcode
-      class ANodeIt : public Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        ANodeIt() { }
-        /// Copy constructor.
-        
-        /// Copy constructor.
-        ///
-        ANodeIt(const ANodeIt& n) : Node(n) { }
-        /// Invalid constructor \& conversion.
-
-        /// Initialize the iterator to be invalid.
-        /// \sa Invalid for more details.
-        ANodeIt(Invalid) { }
-        /// Sets the iterator to the first node.
-
-        /// Sets the iterator to the first node of \c g.
-        ///
-        ANodeIt(const BpUGraph&) { }
-        /// Node -> ANodeIt conversion.
-
-        /// Sets the iterator to the node of \c the graph pointed by 
-	/// the trivial iterator.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        ANodeIt(const BpUGraph&, const Node&) { }
-        /// Next node.
-
-        /// Assign the iterator to the next node.
-        ///
-        ANodeIt& operator++() { return *this; }
-      };
-
-      /// This iterator goes through each BNode.
-
-      /// This iterator goes through each BNode.
-      /// Its usage is quite simple, for example you can count the number
-      /// of nodes in graph \c g of type \c Graph like this:
-      ///\code
-      /// int count=0;
-      /// for (Graph::BNodeIt n(g); n!=INVALID; ++n) ++count;
-      ///\endcode
-      class BNodeIt : public Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        BNodeIt() { }
-        /// Copy constructor.
-        
-        /// Copy constructor.
-        ///
-        BNodeIt(const BNodeIt& n) : Node(n) { }
-        /// Invalid constructor \& conversion.
-
-        /// Initialize the iterator to be invalid.
-        /// \sa Invalid for more details.
-        BNodeIt(Invalid) { }
-        /// Sets the iterator to the first node.
-
-        /// Sets the iterator to the first node of \c g.
-        ///
-        BNodeIt(const BpUGraph&) { }
-        /// Node -> BNodeIt conversion.
-
-        /// Sets the iterator to the node of \c the graph pointed by 
-	/// the trivial iterator.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        BNodeIt(const BpUGraph&, const Node&) { }
-        /// Next node.
-
-        /// Assign the iterator to the next node.
-        ///
-        BNodeIt& operator++() { return *this; }
-      };
-    
-    
-      /// The base type of the undirected edge iterators.
-
-      /// The base type of the undirected edge iterators.
-      ///
-      class UEdge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        UEdge() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        UEdge(const UEdge&) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        UEdge(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(UEdge) const { return true; }
-        /// Inequality operator
-
-        /// \sa operator==(UEdge n)
-        ///
-        bool operator!=(UEdge) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(UEdge) const { return false; }
-      };
-
-      /// This iterator goes through each undirected edge.
-
-      /// This iterator goes through each undirected edge of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of undirected edges in a graph \c g of type \c Graph as follows:
-      ///\code
-      /// int count=0;
-      /// for(Graph::UEdgeIt e(g); e!=INVALID; ++e) ++count;
-      ///\endcode
-      class UEdgeIt : public UEdge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        UEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        UEdgeIt(const UEdgeIt& e) : UEdge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        UEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first undirected edge.
-    
-        /// This constructor sets the iterator to the first undirected edge.
-        UEdgeIt(const BpUGraph&) { }
-        /// UEdge -> UEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator.
-        /// This feature necessitates that each time we
-        /// iterate the undirected edge-set, the iteration order is the 
-	/// same.
-        UEdgeIt(const BpUGraph&, const UEdge&) { } 
-        /// Next undirected edge
-        
-        /// Assign the iterator to the next undirected edge.
-        UEdgeIt& operator++() { return *this; }
-      };
-
-      /// \brief This iterator goes trough the incident undirected 
-      /// edges of a node.
-      ///
-      /// This iterator goes trough the incident undirected edges
-      /// of a certain node
-      /// of a graph.
-      /// Its usage is quite simple, for example you can compute the
-      /// degree (i.e. count the number
-      /// of incident edges of a node \c n
-      /// in graph \c g of type \c Graph as follows.
-      ///\code
-      /// int count=0;
-      /// for(Graph::IncEdgeIt e(g, n); e!=INVALID; ++e) ++count;
-      ///\endcode
-      class IncEdgeIt : public UEdge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        IncEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        IncEdgeIt(const IncEdgeIt& e) : UEdge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        IncEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to first incident edge.
-    
-        /// This constructor set the iterator to the first incident edge of
-        /// the node.
-        IncEdgeIt(const BpUGraph&, const Node&) { }
-        /// UEdge -> IncEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        IncEdgeIt(const BpUGraph&, const UEdge&) { }
-        /// Next incident edge
-
-        /// Assign the iterator to the next incident edge
-	/// of the corresponding node.
-        IncEdgeIt& operator++() { return *this; }
-      };
-
-      /// The directed edge type.
-
-      /// The directed edge type. It can be converted to the
-      /// undirected edge.
-      class Edge : public UEdge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        Edge() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        Edge(const Edge& e) : UEdge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        Edge(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(Edge) const { return true; }
-        /// Inequality operator
-
-        /// \sa operator==(Edge n)
-        ///
-        bool operator!=(Edge) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(Edge) const { return false; }
-	
-      }; 
-      /// This iterator goes through each directed edge.
-
-      /// This iterator goes through each edge of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of edges in a graph \c g of type \c Graph as follows:
-      ///\code
-      /// int count=0;
-      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
-      ///\endcode
-      class EdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        EdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        EdgeIt(const EdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        EdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first edge.
-    
-        /// This constructor sets the iterator to the first edge of \c g.
-        ///@param g the graph
-        EdgeIt(const BpUGraph &g) { ignore_unused_variable_warning(g); }
-        /// Edge -> EdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        EdgeIt(const BpUGraph&, const Edge&) { } 
-        ///Next edge
-        
-        /// Assign the iterator to the next edge.
-        EdgeIt& operator++() { return *this; }
-      };
-   
-      /// This iterator goes trough the outgoing directed edges of a node.
-
-      /// This iterator goes trough the \e outgoing edges of a certain node
-      /// of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of outgoing edges of a node \c n
-      /// in graph \c g of type \c Graph as follows.
-      ///\code
-      /// int count=0;
-      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
-      ///\endcode
-    
-      class OutEdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        OutEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        OutEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first outgoing edge.
-    
-        /// This constructor sets the iterator to the first outgoing edge of
-        /// the node.
-        ///@param n the node
-        ///@param g the graph
-        OutEdgeIt(const BpUGraph& n, const Node& g) {
-	  ignore_unused_variable_warning(n);
-	  ignore_unused_variable_warning(g);
-	}
-        /// Edge -> OutEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator.
-	/// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        OutEdgeIt(const BpUGraph&, const Edge&) { }
-        ///Next outgoing edge
-        
-        /// Assign the iterator to the next 
-        /// outgoing edge of the corresponding node.
-        OutEdgeIt& operator++() { return *this; }
-      };
-
-      /// This iterator goes trough the incoming directed edges of a node.
-
-      /// This iterator goes trough the \e incoming edges of a certain node
-      /// of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of outgoing edges of a node \c n
-      /// in graph \c g of type \c Graph as follows.
-      ///\code
-      /// int count=0;
-      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
-      ///\endcode
-
-      class InEdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        InEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        InEdgeIt(const InEdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        InEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to first incoming edge.
-    
-        /// This constructor set the iterator to the first incoming edge of
-        /// the node.
-        ///@param n the node
-        ///@param g the graph
-        InEdgeIt(const BpUGraph& g, const Node& n) { 
-	  ignore_unused_variable_warning(n);
-	  ignore_unused_variable_warning(g);
-	}
-        /// Edge -> InEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        InEdgeIt(const BpUGraph&, const Edge&) { }
-        /// Next incoming edge
-
-        /// Assign the iterator to the next inedge of the corresponding node.
-        ///
-        InEdgeIt& operator++() { return *this; }
-      };
-
-      /// \brief Read write map of the nodes to type \c T.
-      /// 
-      /// ReadWrite map of the nodes to type \c T.
-      /// \sa Reference
-      /// \warning Making maps that can handle bool type (NodeMap<bool>)
-      /// needs some extra attention!
-      /// \todo Wrong documentation
-      template<class T> 
-      class NodeMap : public ReadWriteMap< Node, T >
-      {
-      public:
-
-        ///\e
-        NodeMap(const BpUGraph&) { }
-        ///\e
-        NodeMap(const BpUGraph&, T) { }
-
-        ///Copy constructor
-        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
-        ///Assignment operator
-        NodeMap& operator=(const NodeMap&) { return *this; }
-        ///Assignment operator
-        template <typename CMap>
-        NodeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Node, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// \brief Read write map of the ANodes to type \c T.
-      /// 
-      /// ReadWrite map of the ANodes to type \c T.
-      /// \sa Reference
-      /// \warning Making maps that can handle bool type (NodeMap<bool>)
-      /// needs some extra attention!
-      /// \todo Wrong documentation
-      template<class T> 
-      class ANodeMap : public ReadWriteMap< Node, T >
-      {
-      public:
-
-        ///\e
-        ANodeMap(const BpUGraph&) { }
-        ///\e
-        ANodeMap(const BpUGraph&, T) { }
-
-        ///Copy constructor
-        ANodeMap(const ANodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
-        ///Assignment operator
-        ANodeMap& operator=(const ANodeMap&) { return *this; }
-        ///Assignment operator
-        template <typename CMap>
-        ANodeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Node, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// \brief Read write map of the BNodes to type \c T.
-      /// 
-      /// ReadWrite map of the BNodes to type \c T.
-      /// \sa Reference
-      /// \warning Making maps that can handle bool type (NodeMap<bool>)
-      /// needs some extra attention!
-      /// \todo Wrong documentation
-      template<class T> 
-      class BNodeMap : public ReadWriteMap< Node, T >
-      {
-      public:
-
-        ///\e
-        BNodeMap(const BpUGraph&) { }
-        ///\e
-        BNodeMap(const BpUGraph&, T) { }
-
-        ///Copy constructor
-        BNodeMap(const BNodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
-        ///Assignment operator
-        BNodeMap& operator=(const BNodeMap&) { return *this; }
-        ///Assignment operator
-        template <typename CMap>
-        BNodeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Node, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// \brief Read write map of the directed edges to type \c T.
-      ///
-      /// Reference map of the directed edges to type \c T.
-      /// \sa Reference
-      /// \warning Making maps that can handle bool type (EdgeMap<bool>)
-      /// needs some extra attention!
-      /// \todo Wrong documentation
-      template<class T> 
-      class EdgeMap : public ReadWriteMap<Edge,T>
-      {
-      public:
-
-        ///\e
-        EdgeMap(const BpUGraph&) { }
-        ///\e
-        EdgeMap(const BpUGraph&, T) { }
-        ///Copy constructor
-        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }
-        ///Assignment operator
-        EdgeMap& operator=(const EdgeMap&) { return *this; }
-        ///Assignment operator
-        template <typename CMap>
-        EdgeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Edge, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// Read write map of the undirected edges to type \c T.
-
-      /// Reference map of the edges to type \c T.
-      /// \sa Reference
-      /// \warning Making maps that can handle bool type (UEdgeMap<bool>)
-      /// needs some extra attention!
-      /// \todo Wrong documentation
-      template<class T> 
-      class UEdgeMap : public ReadWriteMap<UEdge,T>
-      {
-      public:
-
-        ///\e
-        UEdgeMap(const BpUGraph&) { }
-        ///\e
-        UEdgeMap(const BpUGraph&, T) { }
-        ///Copy constructor
-        UEdgeMap(const UEdgeMap& em) : ReadWriteMap<UEdge,T>(em) {}
-        ///Assignment operator
-        UEdgeMap &operator=(const UEdgeMap&) { return *this; }
-        ///Assignment operator
-        template <typename CMap>
-        UEdgeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<UEdge, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// \brief Direct the given undirected edge.
-      ///
-      /// Direct the given undirected edge. The returned edge source
-      /// will be the given node.
-      Edge direct(const UEdge&, const Node&) const {
-	return INVALID;
-      }
-
-      /// \brief Direct the given undirected edge.
-      ///
-      /// Direct the given undirected edge. The returned edge
-      /// represents the given undireted edge and the direction comes
-      /// from the given bool.  The source of the undirected edge and
-      /// the directed edge is the same when the given bool is true.
-      Edge direct(const UEdge&, bool) const {
-	return INVALID;
-      }
-
-      /// \brief Returns true when the given node is an ANode.
-      ///
-      /// Returns true when the given node is an ANode.
-      bool aNode(Node) const { return true;}
-
-      /// \brief Returns true when the given node is an BNode.
-      ///
-      /// Returns true when the given node is an BNode.
-      bool bNode(Node) const { return true;}
-
-      /// \brief Returns the edge's end node which is in the ANode set.
-      ///
-      /// Returns the edge's end node which is in the ANode set.
-      Node aNode(UEdge) const { return INVALID;}
-
-      /// \brief Returns the edge's end node which is in the BNode set.
-      ///
-      /// Returns the edge's end node which is in the BNode set.
-      Node bNode(UEdge) const { return INVALID;}
-
-      /// \brief Returns true if the edge has default orientation.
-      ///
-      /// Returns whether the given directed edge is same orientation as
-      /// the corresponding undirected edge's default orientation.
-      bool direction(Edge) const { return true; }
-
-      /// \brief Returns the opposite directed edge.
-      ///
-      /// Returns the opposite directed edge.
-      Edge oppositeEdge(Edge) const { return INVALID; }
-
-      /// \brief Opposite node on an edge
-      ///
-      /// \return the opposite of the given Node on the given UEdge
-      Node oppositeNode(Node, UEdge) const { return INVALID; }
-
-      /// \brief First node of the undirected edge.
-      ///
-      /// \return the first node of the given UEdge.
-      ///
-      /// Naturally undirected edges don't have direction and thus
-      /// don't have source and target node. But we use these two methods
-      /// to query the two endnodes of the edge. The direction of the edge
-      /// which arises this way is called the inherent direction of the
-      /// undirected edge, and is used to define the "default" direction
-      /// of the directed versions of the edges.
-      /// \sa direction
-      Node source(UEdge) const { return INVALID; }
-
-      /// \brief Second node of the undirected edge.
-      Node target(UEdge) const { return INVALID; }
-
-      /// \brief Source node of the directed edge.
-      Node source(Edge) const { return INVALID; }
-
-      /// \brief Target node of the directed edge.
-      Node target(Edge) const { return INVALID; }
-
-      /// \brief Base node of the iterator
-      ///
-      /// Returns the base node (the source in this case) of the iterator
-      Node baseNode(OutEdgeIt e) const {
-	return source(e);
-      }
-
-      /// \brief Running node of the iterator
-      ///
-      /// Returns the running node (the target in this case) of the
-      /// iterator
-      Node runningNode(OutEdgeIt e) const {
-	return target(e);
-      }
-
-      /// \brief Base node of the iterator
-      ///
-      /// Returns the base node (the target in this case) of the iterator
-      Node baseNode(InEdgeIt e) const {
-	return target(e);
-      }
-      /// \brief Running node of the iterator
-      ///
-      /// Returns the running node (the source in this case) of the
-      /// iterator
-      Node runningNode(InEdgeIt e) const {
-	return source(e);
-      }
-
-      /// \brief Base node of the iterator
-      ///
-      /// Returns the base node of the iterator
-      Node baseNode(IncEdgeIt) const {
-	return INVALID;
-      }
-      
-      /// \brief Running node of the iterator
-      ///
-      /// Returns the running node of the iterator
-      Node runningNode(IncEdgeIt) const {
-	return INVALID;
-      }
-
-      void first(Node&) const {}
-      void next(Node&) const {}
-
-      void first(Edge&) const {}
-      void next(Edge&) const {}
-
-      void first(UEdge&) const {}
-      void next(UEdge&) const {}
-
-      void firstANode(Node&) const {}
-      void nextANode(Node&) const {}
-
-      void firstBNode(Node&) const {}
-      void nextBNode(Node&) const {}
-
-      void firstIn(Edge&, const Node&) const {}
-      void nextIn(Edge&) const {}
-
-      void firstOut(Edge&, const Node&) const {}
-      void nextOut(Edge&) const {}
-
-      void firstInc(UEdge &, bool &, const Node &) const {}
-      void nextInc(UEdge &, bool &) const {}
-
-      void firstFromANode(UEdge&, const Node&) const {}
-      void nextFromANode(UEdge&) const {}
-
-      void firstFromBNode(UEdge&, const Node&) const {}
-      void nextFromBNode(UEdge&) const {}
-
-      template <typename Graph>
-      struct Constraints {
-	void constraints() {
-	  checkConcept<IterableBpUGraphComponent<>, Graph>();
-	  checkConcept<MappableBpUGraphComponent<>, Graph>();
-	}
-      };
-
-    };
-
-
-    /// @}
-
-  }
-
-}
-
-#endif
Index: lemon/concept/graph.h
===================================================================
--- lemon/concept/graph.h	(revision 2231)
+++ 	(revision )
@@ -1,455 +1,0 @@
-/* -*- C++ -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library
- *
- * Copyright (C) 2003-2006
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-#ifndef LEMON_CONCEPT_GRAPH_H
-#define LEMON_CONCEPT_GRAPH_H
-
-///\ingroup graph_concepts
-///\file
-///\brief Declaration of Graph.
-
-#include <lemon/bits/invalid.h>
-#include <lemon/bits/utility.h>
-#include <lemon/concept/maps.h>
-#include <lemon/concept_check.h>
-#include <lemon/concept/graph_components.h>
-
-namespace lemon {
-  namespace concept {
-
-    /// \addtogroup graph_concepts
-    /// @{
-
-    /// The directed graph concept
-
-    /// This class describes the \ref concept "concept" of the
-    /// immutable directed graphs.
-    ///
-    /// Note that actual graph implementation like @ref ListGraph or
-    /// @ref SmartGraph may have several additional functionality.
-    ///
-    /// \sa concept
-    class Graph {
-    private:
-      ///Graphs are \e not copy constructible. Use GraphCopy() instead.
-      
-      ///Graphs are \e not copy constructible. Use GraphCopy() instead.
-      ///
-      Graph(const Graph &) {};
-      ///\brief Assignment of \ref Graph "Graph"s to another ones are
-      ///\e not allowed. Use GraphCopy() instead.
-      
-      ///Assignment of \ref Graph "Graph"s to another ones are
-      ///\e not allowed.  Use GraphCopy() instead.
-
-      void operator=(const Graph &) {}
-    public:
-      ///\e
-
-      /// Defalult constructor.
-
-      /// Defalult constructor.
-      ///
-      Graph() { }
-      /// Class for identifying a node of the graph
-
-      /// This class identifies a node of the graph. It also serves
-      /// as a base class of the node iterators,
-      /// thus they will convert to this type.
-      class Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        Node() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        Node(const Node&) { }
-
-        /// Invalid constructor \& conversion.
-
-        /// This constructor initializes the iterator to be invalid.
-        /// \sa Invalid for more details.
-        Node(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(Node) const { return true; }
-
-        /// Inequality operator
-        
-        /// \sa operator==(Node n)
-        ///
-        bool operator!=(Node) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(Node) const { return false; }
-
-      };
-    
-      /// This iterator goes through each node.
-
-      /// This iterator goes through each node.
-      /// Its usage is quite simple, for example you can count the number
-      /// of nodes in graph \c g of type \c Graph like this:
-      ///\code
-      /// int count=0;
-      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
-      ///\endcode
-      class NodeIt : public Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        NodeIt() { }
-        /// Copy constructor.
-        
-        /// Copy constructor.
-        ///
-        NodeIt(const NodeIt& n) : Node(n) { }
-        /// Invalid constructor \& conversion.
-
-        /// Initialize the iterator to be invalid.
-        /// \sa Invalid for more details.
-        NodeIt(Invalid) { }
-        /// Sets the iterator to the first node.
-
-        /// Sets the iterator to the first node of \c g.
-        ///
-        NodeIt(const Graph&) { }
-        /// Node -> NodeIt conversion.
-
-        /// Sets the iterator to the node of \c the graph pointed by 
-	/// the trivial iterator.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        NodeIt(const Graph&, const Node&) { }
-        /// Next node.
-
-        /// Assign the iterator to the next node.
-        ///
-        NodeIt& operator++() { return *this; }
-      };
-    
-    
-      /// Class for identifying an edge of the graph
-
-      /// This class identifies an edge of the graph. It also serves
-      /// as a base class of the edge iterators,
-      /// thus they will convert to this type.
-      class Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        Edge() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        Edge(const Edge&) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        Edge(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(Edge) const { return true; }
-        /// Inequality operator
-
-        /// \sa operator==(Edge n)
-        ///
-        bool operator!=(Edge) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(Edge) const { return false; }
-      };
-    
-      /// This iterator goes trough the outgoing edges of a node.
-
-      /// This iterator goes trough the \e outgoing edges of a certain node
-      /// of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of outgoing edges of a node \c n
-      /// in graph \c g of type \c Graph as follows.
-      ///\code
-      /// int count=0;
-      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
-      ///\endcode
-    
-      class OutEdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        OutEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        OutEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first outgoing edge.
-    
-        /// This constructor sets the iterator to the first outgoing edge of
-        /// the node.
-        OutEdgeIt(const Graph&, const Node&) { }
-        /// Edge -> OutEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator.
-	/// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        OutEdgeIt(const Graph&, const Edge&) { }
-        ///Next outgoing edge
-        
-        /// Assign the iterator to the next 
-        /// outgoing edge of the corresponding node.
-        OutEdgeIt& operator++() { return *this; }
-      };
-
-      /// This iterator goes trough the incoming edges of a node.
-
-      /// This iterator goes trough the \e incoming edges of a certain node
-      /// of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of outgoing edges of a node \c n
-      /// in graph \c g of type \c Graph as follows.
-      ///\code
-      /// int count=0;
-      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
-      ///\endcode
-
-      class InEdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        InEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        InEdgeIt(const InEdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        InEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to first incoming edge.
-    
-        /// This constructor set the iterator to the first incoming edge of
-        /// the node.
-        InEdgeIt(const Graph&, const Node&) { }
-        /// Edge -> InEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        InEdgeIt(const Graph&, const Edge&) { }
-        /// Next incoming edge
-
-        /// Assign the iterator to the next inedge of the corresponding node.
-        ///
-        InEdgeIt& operator++() { return *this; }
-      };
-      /// This iterator goes through each edge.
-
-      /// This iterator goes through each edge of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of edges in a graph \c g of type \c Graph as follows:
-      ///\code
-      /// int count=0;
-      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
-      ///\endcode
-      class EdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        EdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        EdgeIt(const EdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        EdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first edge.
-    
-        /// This constructor sets the iterator to the first edge of \c g.
-        ///@param g the graph
-        EdgeIt(const Graph& g) { ignore_unused_variable_warning(g); }
-        /// Edge -> EdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        EdgeIt(const Graph&, const Edge&) { } 
-        ///Next edge
-        
-        /// Assign the iterator to the next edge.
-        EdgeIt& operator++() { return *this; }
-      };
-      ///Gives back the target node of an edge.
-
-      ///Gives back the target node of an edge.
-      ///
-      Node target(Edge) const { return INVALID; }
-      ///Gives back the source node of an edge.
-
-      ///Gives back the source node of an edge.
-      ///
-      Node source(Edge) const { return INVALID; }
-
-      void first(Node&) const {}
-      void next(Node&) const {}
-
-      void first(Edge&) const {}
-      void next(Edge&) const {}
-
-
-      void firstIn(Edge&, const Node&) const {}
-      void nextIn(Edge&) const {}
-
-      void firstOut(Edge&, const Node&) const {}
-      void nextOut(Edge&) const {}
-
-      /// \brief The base node of the iterator.
-      ///
-      /// Gives back the base node of the iterator.
-      /// It is always the target of the pointed edge.
-      Node baseNode(const InEdgeIt&) const { return INVALID; }
-
-      /// \brief The running node of the iterator.
-      ///
-      /// Gives back the running node of the iterator.
-      /// It is always the source of the pointed edge.
-      Node runningNode(const InEdgeIt&) const { return INVALID; }
-
-      /// \brief The base node of the iterator.
-      ///
-      /// Gives back the base node of the iterator.
-      /// It is always the source of the pointed edge.
-      Node baseNode(const OutEdgeIt&) const { return INVALID; }
-
-      /// \brief The running node of the iterator.
-      ///
-      /// Gives back the running node of the iterator.
-      /// It is always the target of the pointed edge.
-      Node runningNode(const OutEdgeIt&) const { return INVALID; }
-
-      /// \brief The opposite node on the given edge.
-      ///
-      /// Gives back the opposite node on the given edge.
-      Node oppositeNode(const Node&, const Edge&) const { return INVALID; }
-
-      /// \brief Read write map of the nodes to type \c T.
-      /// 
-      /// ReadWrite map of the nodes to type \c T.
-      /// \sa Reference
-      template<class T> 
-      class NodeMap : public ReadWriteMap< Node, T > {
-      public:
-
-        ///\e
-        NodeMap(const Graph&) { }
-        ///\e
-        NodeMap(const Graph&, T) { }
-
-        ///Copy constructor
-        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
-        ///Assignment operator
-        template <typename CMap>
-        NodeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Node, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// \brief Read write map of the edges to type \c T.
-      ///
-      /// Reference map of the edges to type \c T.
-      /// \sa Reference
-      template<class T> 
-      class EdgeMap : public ReadWriteMap<Edge,T> {
-      public:
-
-        ///\e
-        EdgeMap(const Graph&) { }
-        ///\e
-        EdgeMap(const Graph&, T) { }
-        ///Copy constructor
-        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }
-        ///Assignment operator
-        template <typename CMap>
-        EdgeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Edge, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      template <typename RGraph>
-      struct Constraints {
-        void constraints() {
-          checkConcept<IterableGraphComponent<>, Graph>();
-          checkConcept<MappableGraphComponent<>, Graph>();
-        }
-      };
-
-    };
-    
-    // @}
-  } //namespace concept  
-} //namespace lemon
-
-
-
-#endif // LEMON_CONCEPT_GRAPH_H
Index: lemon/concept/graph_components.h
===================================================================
--- lemon/concept/graph_components.h	(revision 2231)
+++ 	(revision )
@@ -1,2103 +1,0 @@
-/* -*- C++ -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library
- *
- * Copyright (C) 2003-2006
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-///\ingroup graph_concepts
-///\file
-///\brief The concept of the graph components.
-
-
-#ifndef LEMON_CONCEPT_GRAPH_COMPONENTS_H
-#define LEMON_CONCEPT_GRAPH_COMPONENTS_H
-
-#include <lemon/bits/invalid.h>
-#include <lemon/concept/maps.h>
-
-#include <lemon/bits/alteration_notifier.h>
-
-namespace lemon {
-  namespace concept {
-
-    /// \brief Skeleton class for graph Node and Edge types
-    ///
-    /// This class describes the interface of Node and Edge (and UEdge
-    /// in undirected graphs) subtypes of graph types.
-    ///
-    /// \note This class is a template class so that we can use it to
-    /// create graph skeleton classes. The reason for this is than Node
-    /// and Edge types should \em not derive from the same base class.
-    /// For Node you should instantiate it with character 'n' and for Edge
-    /// with 'e'.
-
-#ifndef DOXYGEN
-    template <char _selector = '0'>
-#endif
-    class GraphItem {
-    public:
-      /// \brief Default constructor.
-      ///      
-      /// \warning The default constructor is not required to set
-      /// the item to some well-defined value. So you should consider it
-      /// as uninitialized.
-      GraphItem() {}
-      /// \brief Copy constructor.
-      ///
-      /// Copy constructor.
-      ///
-      GraphItem(const GraphItem &) {}
-      /// \brief Invalid constructor \& conversion.
-      ///
-      /// This constructor initializes the item to be invalid.
-      /// \sa Invalid for more details.
-      GraphItem(Invalid) {}
-      /// \brief Assign operator for nodes.
-      ///
-      /// The nodes are assignable. 
-      ///
-      GraphItem& operator=(GraphItem const&) { return *this; }
-      /// \brief Equality operator.
-      ///
-      /// Two iterators are equal if and only if they represents the
-      /// same node in the graph or both are invalid.
-      bool operator==(GraphItem) const { return false; }
-      /// \brief Inequality operator.
-      ///
-      /// \sa operator==(const Node& n)
-      ///
-      bool operator!=(GraphItem) const { return false; }
-
-      /// \brief Artificial ordering operator.
-      ///
-      /// To allow the use of graph descriptors as key type in std::map or
-      /// similar associative container we require this.
-      ///
-      /// \note This operator only have to define some strict ordering of
-      /// the items; this order has nothing to do with the iteration
-      /// ordering of the items.
-      bool operator<(GraphItem) const { return false; }
-
-      template<typename _GraphItem>
-      struct Constraints {
-	void constraints() {
-	  _GraphItem i1;
-	  _GraphItem i2 = i1;
-	  _GraphItem i3 = INVALID;
-	  
-	  i1 = i2 = i3;
-
-	  bool b;
-	  //	  b = (ia == ib) && (ia != ib) && (ia < ib);
-	  b = (ia == ib) && (ia != ib);
-	  b = (ia == INVALID) && (ib != INVALID);
-          b = (ia < ib);
-	}
-
-	const _GraphItem &ia;
-	const _GraphItem &ib;
-      };
-    };
-
-    /// \brief An empty base graph class.
-    ///  
-    /// This class provides the minimal set of features needed for a graph
-    /// structure. All graph concepts have to be conform to this base
-    /// graph. It just provides types for nodes and edges and functions to
-    /// get the source and the target of the edges.
-    class BaseGraphComponent {
-    public:
-
-      typedef BaseGraphComponent Graph;
-      
-      /// \brief Node class of the graph.
-      ///
-      /// This class represents the Nodes of the graph. 
-      ///
-      typedef GraphItem<'n'> Node;
-
-      /// \brief Edge class of the graph.
-      ///
-      /// This class represents the Edges of the graph. 
-      ///
-      typedef GraphItem<'e'> Edge;
-
-      /// \brief Gives back the target node of an edge.
-      ///
-      /// Gives back the target node of an edge.
-      ///
-      Node target(const Edge&) const { return INVALID;}
-
-      /// \brief Gives back the source node of an edge.
-      ///
-      /// Gives back the source node of an edge.
-      ///
-      Node source(const Edge&) const { return INVALID;}
-
-      /// \brief Gives back the opposite node on the given edge.
-      ///
-      /// Gives back the opposite node on the given edge.
-      Node oppositeNode(const Node&, const Edge&) const {
-        return INVALID;
-      }
-
-      template <typename _Graph>
-      struct Constraints {
-	typedef typename _Graph::Node Node;
-	typedef typename _Graph::Edge Edge;
-      
-	void constraints() {
-	  checkConcept<GraphItem<'n'>, Node>();
-	  checkConcept<GraphItem<'e'>, Edge>();
-	  {
-	    Node n;
-	    Edge e(INVALID);
-	    n = graph.source(e);
-	    n = graph.target(e);
-            n = graph.oppositeNode(n, e);
-	  }      
-	}
-      
-	const _Graph& graph;
-      };
-    };
-
-    /// \brief An empty base undirected graph class.
-    ///  
-    /// This class provides the minimal set of features needed for an
-    /// undirected graph structure. All undirected graph concepts have
-    /// to be conform to this base graph. It just provides types for
-    /// nodes, edges and undirected edges and functions to get the
-    /// source and the target of the edges and undirected edges,
-    /// conversion from edges to undirected edges and function to get
-    /// both direction of the undirected edges.
-    class BaseUGraphComponent : public BaseGraphComponent {
-    public:
-      typedef BaseGraphComponent::Node Node;
-      typedef BaseGraphComponent::Edge Edge;
-      /// \brief Undirected edge class of the graph.
-      ///
-      /// This class represents the undirected edges of the graph.
-      /// The undirected graphs can be used as a directed graph which
-      /// for each edge contains the opposite edge too so the graph is
-      /// bidirected. The undirected edge represents two opposite
-      /// directed edges.
-      class UEdge : public GraphItem<'u'> {
-      public:
-        typedef GraphItem<'u'> Parent;
-        /// \brief Default constructor.
-        ///      
-        /// \warning The default constructor is not required to set
-        /// the item to some well-defined value. So you should consider it
-        /// as uninitialized.
-        UEdge() {}
-        /// \brief Copy constructor.
-        ///
-        /// Copy constructor.
-        ///
-        UEdge(const UEdge &) : Parent() {}
-        /// \brief Invalid constructor \& conversion.
-        ///
-        /// This constructor initializes the item to be invalid.
-        /// \sa Invalid for more details.
-        UEdge(Invalid) {}
-        /// \brief Converter from edge to undirected edge.
-        ///
-        /// Besides the core graph item functionality each edge should
-        /// be convertible to the represented undirected edge. 
-        UEdge(const Edge&) {}
-        /// \brief Assign edge to undirected edge.
-        ///
-        /// Besides the core graph item functionality each edge should
-        /// be convertible to the represented undirected edge. 
-        UEdge& operator=(const Edge&) { return *this; }
-      };
-
-      /// \brief Returns the direction of the edge.
-      ///
-      /// Returns the direction of the edge. Each edge represents an
-      /// undirected edge with a direction. It gives back the
-      /// direction.
-      bool direction(const Edge&) const { return true; }
-
-      /// \brief Returns the directed edge.
-      ///
-      /// Returns the directed edge from its direction and the
-      /// represented undirected edge.
-      Edge direct(const UEdge&, bool) const { return INVALID;} 
-
-      /// \brief Returns the directed edge.
-      ///
-      /// Returns the directed edge from its source and the
-      /// represented undirected edge.
-      Edge direct(const UEdge&, const Node&) const { return INVALID;} 
-
-      /// \brief Returns the opposite edge.
-      ///
-      /// Returns the opposite edge. It is the edge representing the
-      /// same undirected edge and has opposite direction.
-      Edge oppositeEdge(const Edge&) const { return INVALID;}
-
-      /// \brief Gives back the target node of an undirected edge.
-      ///
-      /// Gives back the target node of an undirected edge. The name
-      /// target is a little confusing because the undirected edge
-      /// does not have target but it just means that one of the end 
-      /// node.
-      Node target(const UEdge&) const { return INVALID;}
-
-      /// \brief Gives back the source node of an undirected edge.
-      ///
-      /// Gives back the source node of an undirected edge. The name
-      /// source is a little confusing because the undirected edge
-      /// does not have source but it just means that one of the end 
-      /// node.
-      Node source(const UEdge&) const { return INVALID;}
-      
-      template <typename _Graph>
-      struct Constraints {
-	typedef typename _Graph::Node Node;
-	typedef typename _Graph::Edge Edge;
-	typedef typename _Graph::UEdge UEdge;
-      
-	void constraints() {
-          checkConcept<BaseGraphComponent, _Graph>();
-	  checkConcept<GraphItem<'u'>, UEdge>();
-	  {
-	    Node n;
-	    UEdge ue(INVALID);
-            Edge e;
-	    n = graph.source(ue);
-	    n = graph.target(ue);
-            e = graph.direct(ue, true);
-            e = graph.direct(ue, n);
-            e = graph.oppositeEdge(e);
-            ue = e;
-            bool d = graph.direction(e);
-            ignore_unused_variable_warning(d);
-	  }      
-	}
-      
-	const _Graph& graph;
-      };
-
-    };
-
-    /// \brief An empty base bipartite undirected graph class.
-    ///  
-    /// This class provides the minimal set of features needed for an
-    /// bipartite undirected graph structure. All bipartite undirected
-    /// graph concepts have to be conform to this base graph. It just
-    /// provides types for nodes, A-nodes, B-nodes, edges and
-    /// undirected edges and functions to get the source and the
-    /// target of the edges and undirected edges, conversion from
-    /// edges to undirected edges and function to get both direction
-    /// of the undirected edges.
-    class BaseBpUGraphComponent : public BaseUGraphComponent {
-    public:
-      typedef BaseUGraphComponent::Node Node;
-      typedef BaseUGraphComponent::Edge Edge;
-      typedef BaseUGraphComponent::UEdge UEdge;
-
-      /// \brief Helper class for A-nodes.
-      ///
-      /// This class is just a helper class for A-nodes, it is not
-      /// suggested to use it directly. It can be converted easily to
-      /// node and vice versa. The usage of this class is limited
-      /// to use just as template parameters for special map types. 
-      class ANode : public Node {
-      public:
-        typedef Node Parent;
-
-        /// \brief Default constructor.
-        ///      
-        /// \warning The default constructor is not required to set
-        /// the item to some well-defined value. So you should consider it
-        /// as uninitialized.
-        ANode() {}
-        /// \brief Copy constructor.
-        ///
-        /// Copy constructor.
-        ///
-        ANode(const ANode &) : Parent() {}
-        /// \brief Invalid constructor \& conversion.
-        ///
-        /// This constructor initializes the item to be invalid.
-        /// \sa Invalid for more details.
-        ANode(Invalid) {}
-        /// \brief Converter from node to A-node.
-        ///
-        /// Besides the core graph item functionality each node should
-        /// be convertible to the represented A-node if it is it possible. 
-        ANode(const Node&) {}
-        /// \brief Assign node to A-node.
-        ///
-        /// Besides the core graph item functionality each node should
-        /// be convertible to the represented A-node if it is it possible. 
-        ANode& operator=(const Node&) { return *this; }
-      };
-
-      /// \brief Helper class for B-nodes.
-      ///
-      /// This class is just a helper class for B-nodes, it is not
-      /// suggested to use it directly. It can be converted easily to
-      /// node and vice versa. The usage of this class is limited
-      /// to use just as template parameters for special map types. 
-      class BNode : public Node {
-      public:
-        typedef Node Parent;
-
-        /// \brief Default constructor.
-        ///      
-        /// \warning The default constructor is not required to set
-        /// the item to some well-defined value. So you should consider it
-        /// as uninitialized.
-        BNode() {}
-        /// \brief Copy constructor.
-        ///
-        /// Copy constructor.
-        ///
-        BNode(const BNode &) : Parent() {}
-        /// \brief Invalid constructor \& conversion.
-        ///
-        /// This constructor initializes the item to be invalid.
-        /// \sa Invalid for more details.
-        BNode(Invalid) {}
-        /// \brief Converter from node to B-node.
-        ///
-        /// Besides the core graph item functionality each node should
-        /// be convertible to the represented B-node if it is it possible. 
-        BNode(const Node&) {}
-        /// \brief Assign node to B-node.
-        ///
-        /// Besides the core graph item functionality each node should
-        /// be convertible to the represented B-node if it is it possible. 
-        BNode& operator=(const Node&) { return *this; }
-      };
-      
-      /// \brief Gives back %true when the node is A-node.
-      ///
-      /// Gives back %true when the node is A-node.
-      bool aNode(const Node&) const { return false; }
-
-      /// \brief Gives back %true when the node is B-node.
-      ///
-      /// Gives back %true when the node is B-node.
-      bool bNode(const Node&) const { return false; }
-
-      /// \brief Gives back the A-node of the undirected edge.
-      ///
-      /// Gives back the A-node of the undirected edge.
-      Node aNode(const UEdge&) const { return INVALID; }
-
-      /// \brief Gives back the B-node of the undirected edge.
-      ///
-      /// Gives back the B-node of the undirected edge.
-      Node bNode(const UEdge&) const { return INVALID; }
-      
-      template <typename _Graph>
-      struct Constraints {
-	typedef typename _Graph::Node Node;
-	typedef typename _Graph::ANode ANode;
-	typedef typename _Graph::BNode BNode;
-	typedef typename _Graph::Edge Edge;
-	typedef typename _Graph::UEdge UEdge;
-      
-	void constraints() {
-          checkConcept<BaseUGraphComponent, _Graph>();
-	  checkConcept<GraphItem<'a'>, ANode>();
-	  checkConcept<GraphItem<'b'>, BNode>();
-	  {
-	    Node n;
-	    UEdge ue(INVALID);
-            bool b;
-	    n = graph.aNode(ue);
-	    n = graph.bNode(ue);
-            b = graph.aNode(n);
-            b = graph.bNode(n);
-            ANode an;
-            an = n; n = an;
-            BNode bn;
-            bn = n; n = bn;            
-            ignore_unused_variable_warning(b);
-	  }      
-	}
-      
-	const _Graph& graph;
-      };
-
-    };
-
-    /// \brief An empty idable base graph class.
-    ///  
-    /// This class provides beside the core graph features
-    /// core id functions for the graph structure.
-    /// The most of the base graphs should be conform to this concept.
-    /// The id's are unique and immutable.
-    template <typename _Base = BaseGraphComponent>
-    class IDableGraphComponent : public _Base {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-      typedef typename Base::Edge Edge;
-
-      /// \brief Gives back an unique integer id for the Node. 
-      ///
-      /// Gives back an unique integer id for the Node. 
-      ///
-      int id(const Node&) const { return -1;}
-
-      /// \brief Gives back the node by the unique id.
-      ///
-      /// Gives back the node by the unique id.
-      /// If the graph does not contain node with the given id
-      /// then the result of the function is undetermined. 
-      Node nodeFromId(int) const { return INVALID;}
-
-      /// \brief Gives back an unique integer id for the Edge. 
-      ///
-      /// Gives back an unique integer id for the Edge. 
-      ///
-      int id(const Edge&) const { return -1;}
-
-      /// \brief Gives back the edge by the unique id.
-      ///
-      /// Gives back the edge by the unique id.
-      /// If the graph does not contain edge with the given id
-      /// then the result of the function is undetermined. 
-      Edge edgeFromId(int) const { return INVALID;}
-
-      /// \brief Gives back an integer greater or equal to the maximum
-      /// Node id.
-      ///
-      /// Gives back an integer greater or equal to the maximum Node
-      /// id.
-      int maxNodeId() const { return -1;}
-
-      /// \brief Gives back an integer greater or equal to the maximum
-      /// Edge id.
-      ///
-      /// Gives back an integer greater or equal to the maximum Edge
-      /// id.
-      int maxEdgeId() const { return -1;}
-
-      template <typename _Graph>
-      struct Constraints {
-
-	void constraints() {
-	  checkConcept<Base, _Graph >();
-	  typename _Graph::Node node;
-	  int nid = graph.id(node);
-	  nid = graph.id(node);
-	  node = graph.nodeFromId(nid);
-	  typename _Graph::Edge edge;
-	  int eid = graph.id(edge);
-	  eid = graph.id(edge);
-	  edge = graph.edgeFromId(eid);
-
-	  nid = graph.maxNodeId();
-	  ignore_unused_variable_warning(nid);
-	  eid = graph.maxEdgeId();
-	  ignore_unused_variable_warning(eid);
-	}
-
-	const _Graph& graph;
-      };
-    };
-
-    /// \brief An empty idable base undirected graph class.
-    ///  
-    /// This class provides beside the core undirected graph features
-    /// core id functions for the undirected graph structure.  The
-    /// most of the base undirected graphs should be conform to this
-    /// concept.  The id's are unique and immutable.
-    template <typename _Base = BaseUGraphComponent>
-    class IDableUGraphComponent : public IDableGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::UEdge UEdge;
-
-      using IDableGraphComponent<_Base>::id;
-
-      /// \brief Gives back an unique integer id for the UEdge. 
-      ///
-      /// Gives back an unique integer id for the UEdge. 
-      ///
-      int id(const UEdge&) const { return -1;}
-
-      /// \brief Gives back the undirected edge by the unique id.
-      ///
-      /// Gives back the undirected edge by the unique id.  If the
-      /// graph does not contain edge with the given id then the
-      /// result of the function is undetermined.
-      UEdge uEdgeFromId(int) const { return INVALID;}
-
-      /// \brief Gives back an integer greater or equal to the maximum
-      /// UEdge id.
-      ///
-      /// Gives back an integer greater or equal to the maximum UEdge
-      /// id.
-      int maxUEdgeId() const { return -1;}
-
-      template <typename _Graph>
-      struct Constraints {
-
-	void constraints() {
-	  checkConcept<Base, _Graph >();
-	  checkConcept<IDableGraphComponent<Base>, _Graph >();
-	  typename _Graph::UEdge uedge;
-	  int ueid = graph.id(uedge);
-	  ueid = graph.id(uedge);
-	  uedge = graph.uEdgeFromId(ueid);
-	  ueid = graph.maxUEdgeId();
-	  ignore_unused_variable_warning(ueid);
-	}
-
-	const _Graph& graph;
-      };
-    };
-
-    /// \brief An empty idable base bipartite undirected graph class.
-    ///  
-    /// This class provides beside the core bipartite undirected graph
-    /// features core id functions for the bipartite undirected graph
-    /// structure.  The most of the base undirected graphs should be
-    /// conform to this concept.
-    template <typename _Base = BaseBpUGraphComponent>
-    class IDableBpUGraphComponent : public IDableUGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-
-      using IDableUGraphComponent<_Base>::id;
-
-      /// \brief Gives back an unique integer id for the ANode. 
-      ///
-      /// Gives back an unique integer id for the ANode. 
-      ///
-      int aNodeId(const Node&) const { return -1;}
-
-      /// \brief Gives back the undirected edge by the unique id.
-      ///
-      /// Gives back the undirected edge by the unique id.  If the
-      /// graph does not contain edge with the given id then the
-      /// result of the function is undetermined.
-      Node nodeFromANodeId(int) const { return INVALID;}
-
-      /// \brief Gives back an integer greater or equal to the maximum
-      /// ANode id.
-      ///
-      /// Gives back an integer greater or equal to the maximum ANode
-      /// id.
-      int maxANodeId() const { return -1;}
-
-      /// \brief Gives back an unique integer id for the BNode. 
-      ///
-      /// Gives back an unique integer id for the BNode. 
-      ///
-      int bNodeId(const Node&) const { return -1;}
-
-      /// \brief Gives back the undirected edge by the unique id.
-      ///
-      /// Gives back the undirected edge by the unique id.  If the
-      /// graph does not contain edge with the given id then the
-      /// result of the function is undetermined.
-      Node nodeFromBNodeId(int) const { return INVALID;}
-
-      /// \brief Gives back an integer greater or equal to the maximum
-      /// BNode id.
-      ///
-      /// Gives back an integer greater or equal to the maximum BNode
-      /// id.
-      int maxBNodeId() const { return -1;}
-
-      template <typename _Graph>
-      struct Constraints {
-
-	void constraints() {
-	  checkConcept<Base, _Graph >();
-	  checkConcept<IDableGraphComponent<Base>, _Graph >();
-	  typename _Graph::Node node(INVALID);
-	  int id;
-          id = graph.aNodeId(node);
-          id = graph.bNodeId(node);
-          node = graph.nodeFromANodeId(id);
-          node = graph.nodeFromBNodeId(id);
-          id = graph.maxANodeId();
-          id = graph.maxBNodeId();
-	}
-
-	const _Graph& graph;
-      };
-    };
-
-    /// \brief Skeleton class for graph NodeIt and EdgeIt
-    ///
-    /// Skeleton class for graph NodeIt and EdgeIt.
-    ///
-    template <typename _Graph, typename _Item>
-    class GraphItemIt : public _Item {
-    public:
-      /// \brief Default constructor.
-      ///
-      /// @warning The default constructor sets the iterator
-      /// to an undefined value.
-      GraphItemIt() {}
-      /// \brief Copy constructor.
-      ///
-      /// Copy constructor.
-      ///
-      GraphItemIt(const GraphItemIt& ) {}
-      /// \brief Sets the iterator to the first item.
-      ///
-      /// Sets the iterator to the first item of \c the graph.
-      ///
-      explicit GraphItemIt(const _Graph&) {}
-      /// \brief Invalid constructor \& conversion.
-      ///
-      /// This constructor initializes the item to be invalid.
-      /// \sa Invalid for more details.
-      GraphItemIt(Invalid) {}
-      /// \brief Assign operator for items.
-      ///
-      /// The items are assignable. 
-      ///
-      GraphItemIt& operator=(const GraphItemIt&) { return *this; }      
-      /// \brief Next item.
-      /// 
-      /// Assign the iterator to the next item.
-      ///
-      GraphItemIt& operator++() { return *this; }
-      /// \brief Equality operator
-      /// 
-      /// Two iterators are equal if and only if they point to the
-      /// same object or both are invalid.
-      bool operator==(const GraphItemIt&) const { return true;}
-      /// \brief Inequality operator
-      ///	
-      /// \sa operator==(Node n)
-      ///
-      bool operator!=(const GraphItemIt&) const { return true;}
-      
-      template<typename _GraphItemIt>
-      struct Constraints {
-	void constraints() {
-	  _GraphItemIt it1(g);	
-	  _GraphItemIt it2;
-
-	  it2 = ++it1;
-	  ++it2 = it1;
-	  ++(++it1);
-
-	  _Item bi = it1;
-	  bi = it2;
-	}
-	_Graph& g;
-      };
-    };
-
-    /// \brief Skeleton class for graph InEdgeIt and OutEdgeIt
-    ///
-    /// \note Because InEdgeIt and OutEdgeIt may not inherit from the same
-    /// base class, the _selector is a additional template parameter. For 
-    /// InEdgeIt you should instantiate it with character 'i' and for 
-    /// OutEdgeIt with 'o'.
-    template <typename _Graph,
-	      typename _Item = typename _Graph::Edge,
-              typename _Base = typename _Graph::Node, 
-	      char _selector = '0'>
-    class GraphIncIt : public _Item {
-    public:
-      /// \brief Default constructor.
-      ///
-      /// @warning The default constructor sets the iterator
-      /// to an undefined value.
-      GraphIncIt() {}
-      /// \brief Copy constructor.
-      ///
-      /// Copy constructor.
-      ///
-      GraphIncIt(GraphIncIt const& gi) : _Item(gi) {}
-      /// \brief Sets the iterator to the first edge incoming into or outgoing 
-      /// from the node.
-      ///
-      /// Sets the iterator to the first edge incoming into or outgoing 
-      /// from the node.
-      ///
-      explicit GraphIncIt(const _Graph&, const _Base&) {}
-      /// \brief Invalid constructor \& conversion.
-      ///
-      /// This constructor initializes the item to be invalid.
-      /// \sa Invalid for more details.
-      GraphIncIt(Invalid) {}
-      /// \brief Assign operator for iterators.
-      ///
-      /// The iterators are assignable. 
-      ///
-      GraphIncIt& operator=(GraphIncIt const&) { return *this; }      
-      /// \brief Next item.
-      ///
-      /// Assign the iterator to the next item.
-      ///
-      GraphIncIt& operator++() { return *this; }
-
-      /// \brief Equality operator
-      ///
-      /// Two iterators are equal if and only if they point to the
-      /// same object or both are invalid.
-      bool operator==(const GraphIncIt&) const { return true;}
-
-      /// \brief Inequality operator
-      ///
-      /// \sa operator==(Node n)
-      ///
-      bool operator!=(const GraphIncIt&) const { return true;}
-
-      template <typename _GraphIncIt>
-      struct Constraints {
-	void constraints() {
-	  checkConcept<GraphItem<_selector>, _GraphIncIt>();
-	  _GraphIncIt it1(graph, node);
-	  _GraphIncIt it2;
-
-	  it2 = ++it1;
-	  ++it2 = it1;
-	  ++(++it1);
-	  _Item e = it1;
-	  e = it2;
-
-	}
-
-	_Item edge;
-	_Base node;
-	_Graph graph;
-	_GraphIncIt it;
-      };
-    };
-
-
-    /// \brief An empty iterable graph class.
-    ///
-    /// This class provides beside the core graph features
-    /// iterator based iterable interface for the graph structure.
-    /// This concept is part of the Graph concept.
-    template <typename _Base = BaseGraphComponent>
-    class IterableGraphComponent : public _Base {
-
-    public:
-    
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-      typedef typename Base::Edge Edge;
-
-      typedef IterableGraphComponent Graph;
-
-      /// \name Base iteration
-      /// 
-      /// This interface provides functions for iteration on graph items
-      ///
-      /// @{  
-
-      /// \brief Gives back the first node in the iterating order.
-      ///      
-      /// Gives back the first node in the iterating order.
-      ///     
-      void first(Node&) const {}
-
-      /// \brief Gives back the next node in the iterating order.
-      ///
-      /// Gives back the next node in the iterating order.
-      ///     
-      void next(Node&) const {}
-
-      /// \brief Gives back the first edge in the iterating order.
-      ///
-      /// Gives back the first edge in the iterating order.
-      ///     
-      void first(Edge&) const {}
-
-      /// \brief Gives back the next edge in the iterating order.
-      ///
-      /// Gives back the next edge in the iterating order.
-      ///     
-      void next(Edge&) const {}
-
-
-      /// \brief Gives back the first of the edges point to the given
-      /// node.
-      ///
-      /// Gives back the first of the edges point to the given node.
-      ///     
-      void firstIn(Edge&, const Node&) const {}
-
-      /// \brief Gives back the next of the edges points to the given
-      /// node.
-      ///
-      /// Gives back the next of the edges points to the given node.
-      ///
-      void nextIn(Edge&) const {}
-
-      /// \brief Gives back the first of the edges start from the
-      /// given node.
-      ///      
-      /// Gives back the first of the edges start from the given node.
-      ///     
-      void firstOut(Edge&, const Node&) const {}
-
-      /// \brief Gives back the next of the edges start from the given
-      /// node.
-      ///
-      /// Gives back the next of the edges start from the given node.
-      ///     
-      void nextOut(Edge&) const {}
-
-      /// @}
-
-      /// \name Class based iteration
-      /// 
-      /// This interface provides functions for iteration on graph items
-      ///
-      /// @{
-
-      /// \brief This iterator goes through each node.
-      ///
-      /// This iterator goes through each node.
-      ///
-      typedef GraphItemIt<Graph, Node> NodeIt;
-
-      /// \brief This iterator goes through each node.
-      ///
-      /// This iterator goes through each node.
-      ///
-      typedef GraphItemIt<Graph, Edge> EdgeIt;
-
-      /// \brief This iterator goes trough the incoming edges of a node.
-      ///
-      /// This iterator goes trough the \e inccoming edges of a certain node
-      /// of a graph.
-      typedef GraphIncIt<Graph, Edge, Node, 'i'> InEdgeIt;
-
-      /// \brief This iterator goes trough the outgoing edges of a node.
-      ///
-      /// This iterator goes trough the \e outgoing edges of a certain node
-      /// of a graph.
-      typedef GraphIncIt<Graph, Edge, Node, 'o'> OutEdgeIt;
-
-      /// \brief The base node of the iterator.
-      ///
-      /// Gives back the base node of the iterator.
-      /// It is always the target of the pointed edge.
-      Node baseNode(const InEdgeIt&) const { return INVALID; }
-
-      /// \brief The running node of the iterator.
-      ///
-      /// Gives back the running node of the iterator.
-      /// It is always the source of the pointed edge.
-      Node runningNode(const InEdgeIt&) const { return INVALID; }
-
-      /// \brief The base node of the iterator.
-      ///
-      /// Gives back the base node of the iterator.
-      /// It is always the source of the pointed edge.
-      Node baseNode(const OutEdgeIt&) const { return INVALID; }
-
-      /// \brief The running node of the iterator.
-      ///
-      /// Gives back the running node of the iterator.
-      /// It is always the target of the pointed edge.
-      Node runningNode(const OutEdgeIt&) const { return INVALID; }
-
-      /// @}
-
-      template <typename _Graph> 
-      struct Constraints {
-	void constraints() {
-	  checkConcept<Base, _Graph>();
-
-          {
-            typename _Graph::Node node(INVALID);      
-            typename _Graph::Edge edge(INVALID);
-            {
-              graph.first(node);
-              graph.next(node);
-            }
-            {
-              graph.first(edge);
-              graph.next(edge);
-            }
-            {
-              graph.firstIn(edge, node);
-              graph.nextIn(edge);
-            }
-            {
-              graph.firstOut(edge, node);
-              graph.nextOut(edge);
-            }
-          }           
-
-          {
-            checkConcept<GraphItemIt<_Graph, typename _Graph::Edge>,
-              typename _Graph::EdgeIt >();
-            checkConcept<GraphItemIt<_Graph, typename _Graph::Node>,
-              typename _Graph::NodeIt >();
-            checkConcept<GraphIncIt<_Graph, typename _Graph::Edge, 
-              typename _Graph::Node, 'i'>, typename _Graph::InEdgeIt>();
-            checkConcept<GraphIncIt<_Graph, typename _Graph::Edge, 
-              typename _Graph::Node, 'o'>, typename _Graph::OutEdgeIt>();
-
-            typename _Graph::Node n;
-            typename _Graph::InEdgeIt ieit(INVALID);
-            typename _Graph::OutEdgeIt oeit(INVALID);
-            n = graph.baseNode(ieit);
-            n = graph.runningNode(ieit);
-            n = graph.baseNode(oeit);
-            n = graph.runningNode(oeit);
-            ignore_unused_variable_warning(n);
-          }
-        }
-	
-	const _Graph& graph;
-	
-      };
-    };
-
-    /// \brief An empty iterable undirected graph class.
-    ///
-    /// This class provides beside the core graph features iterator
-    /// based iterable interface for the undirected graph structure.
-    /// This concept is part of the UGraph concept.
-    template <typename _Base = BaseUGraphComponent>
-    class IterableUGraphComponent : public IterableGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-      typedef typename Base::Edge Edge;
-      typedef typename Base::UEdge UEdge;
-
-    
-      typedef IterableUGraphComponent Graph;
-
-      /// \name Base iteration
-      /// 
-      /// This interface provides functions for iteration on graph items
-      /// @{  
-
-      using IterableGraphComponent<_Base>::first;
-      using IterableGraphComponent<_Base>::next;
-
-      /// \brief Gives back the first undirected edge in the iterating
-      /// order.
-      ///
-      /// Gives back the first undirected edge in the iterating order.
-      ///     
-      void first(UEdge&) const {}
-
-      /// \brief Gives back the next undirected edge in the iterating
-      /// order.
-      ///
-      /// Gives back the next undirected edge in the iterating order.
-      ///     
-      void next(UEdge&) const {}
-
-
-      /// \brief Gives back the first of the undirected edges from the
-      /// given node.
-      ///
-      /// Gives back the first of the undirected edges from the given
-      /// node. The bool parameter gives back that direction which
-      /// gives a good direction of the uedge so the source of the
-      /// directed edge is the given node.
-      void firstInc(UEdge&, bool&, const Node&) const {}
-
-      /// \brief Gives back the next of the undirected edges from the
-      /// given node.
-      ///
-      /// Gives back the next of the undirected edges from the given
-      /// node. The bool parameter should be used as the \c firstInc()
-      /// use it.
-      void nextInc(UEdge&, bool&) const {}
-
-      using IterableGraphComponent<_Base>::baseNode;
-      using IterableGraphComponent<_Base>::runningNode;
-
-      /// @}
-
-      /// \name Class based iteration
-      /// 
-      /// This interface provides functions for iteration on graph items
-      ///
-      /// @{
-
-      /// \brief This iterator goes through each node.
-      ///
-      /// This iterator goes through each node.
-      typedef GraphItemIt<Graph, UEdge> UEdgeIt;
-      /// \brief This iterator goes trough the incident edges of a
-      /// node.
-      ///
-      /// This iterator goes trough the incident edges of a certain
-      /// node of a graph.
-      typedef GraphIncIt<Graph, UEdge, Node, 'u'> IncEdgeIt;
-      /// \brief The base node of the iterator.
-      ///
-      /// Gives back the base node of the iterator.
-      Node baseNode(const IncEdgeIt&) const { return INVALID; }
-
-      /// \brief The running node of the iterator.
-      ///
-      /// Gives back the running node of the iterator.
-      Node runningNode(const IncEdgeIt&) const { return INVALID; }
-
-      /// @}
-
-      template <typename _Graph> 
-      struct Constraints {
-	void constraints() {
-	  checkConcept<IterableGraphComponent<Base>, _Graph>();
-
-          {
-            typename _Graph::Node node(INVALID);
-            typename _Graph::UEdge uedge(INVALID);
-            bool dir;
-            {
-              graph.first(uedge);
-              graph.next(uedge);
-            }
-            {
-              graph.firstInc(uedge, dir, node);
-              graph.nextInc(uedge, dir);
-            }
-            
-          }	
-  
-          {
-            checkConcept<GraphItemIt<_Graph, typename _Graph::UEdge>,
-              typename _Graph::UEdgeIt >();
-            checkConcept<GraphIncIt<_Graph, typename _Graph::UEdge, 
-              typename _Graph::Node, 'u'>, typename _Graph::IncEdgeIt>();
-            
-            typename _Graph::Node n;
-            typename _Graph::IncEdgeIt ueit(INVALID);
-            n = graph.baseNode(ueit);
-            n = graph.runningNode(ueit);
-          }
-        }
-	
-	const _Graph& graph;
-	
-      };
-    };
-
-    /// \brief An empty iterable bipartite undirected graph class.
-    ///
-    /// This class provides beside the core graph features iterator
-    /// based iterable interface for the bipartite undirected graph
-    /// structure. This concept is part of the BpUGraph concept.
-    template <typename _Base = BaseUGraphComponent>
-    class IterableBpUGraphComponent : public IterableUGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-      typedef typename Base::UEdge UEdge;
-    
-      typedef IterableBpUGraphComponent Graph;
-
-      /// \name Base iteration
-      /// 
-      /// This interface provides functions for iteration on graph items
-      /// @{  
-
-      using IterableUGraphComponent<_Base>::first;
-      using IterableUGraphComponent<_Base>::next;
-
-      /// \brief Gives back the first A-node in the iterating order.
-      ///
-      /// Gives back the first undirected A-node in the iterating
-      /// order.
-      ///     
-      void firstANode(Node&) const {}
-
-      /// \brief Gives back the next A-node in the iterating order.
-      ///
-      /// Gives back the next A-node in the iterating order.
-      ///     
-      void nextANode(Node&) const {}
-
-      /// \brief Gives back the first B-node in the iterating order.
-      ///
-      /// Gives back the first undirected B-node in the iterating
-      /// order.
-      ///     
-      void firstBNode(Node&) const {}
-
-      /// \brief Gives back the next B-node in the iterating order.
-      ///
-      /// Gives back the next B-node in the iterating order.
-      ///     
-      void nextBNode(Node&) const {}
-
-
-      /// \brief Gives back the first of the undirected edges start
-      /// from the given A-node.
-      ///      
-      /// Gives back the first of the undirected edges start from the
-      /// given A-node.
-      void firstFromANode(UEdge&, const Node&) const {}
-
-      /// \brief Gives back the next of the undirected edges start
-      /// from the given A-node.
-      ///      
-      /// Gives back the next of the undirected edges start from the
-      /// given A-node.
-      void nextFromANode(UEdge&) const {}
-
-      /// \brief Gives back the first of the undirected edges start
-      /// from the given B-node.
-      ///      
-      /// Gives back the first of the undirected edges start from the
-      /// given B-node.
-      void firstFromBNode(UEdge&, const Node&) const {}
-
-      /// \brief Gives back the next of the undirected edges start
-      /// from the given B-node.
-      ///      
-      /// Gives back the next of the undirected edges start from the
-      /// given B-node.
-      void nextFromBNode(UEdge&) const {}
-
-
-      /// @}
-
-      /// \name Class based iteration
-      /// 
-      /// This interface provides functions for iteration on graph items
-      ///
-      /// @{
-
-      /// \brief This iterator goes through each A-node.
-      ///
-      /// This iterator goes through each A-node.
-      typedef GraphItemIt<Graph, Node> ANodeIt;
-
-      /// \brief This iterator goes through each B-node.
-      ///
-      /// This iterator goes through each B-node.
-      typedef GraphItemIt<Graph, Node> BNodeIt;
-
-      /// @}
-
-      template <typename _Graph> 
-      struct Constraints {
-	void constraints() {
-	  checkConcept<IterableUGraphComponent<Base>, _Graph>();
-
-          {
-            typename _Graph::Node node(INVALID);
-            typename _Graph::UEdge uedge(INVALID);
-            graph.firstANode(node);
-            graph.nextANode(node);
-            graph.firstBNode(node);
-            graph.nextBNode(node);
-
-            graph.firstFromANode(uedge, node);
-            graph.nextFromANode(uedge);
-            graph.firstFromBNode(uedge, node);
-            graph.nextFromBNode(uedge);
-          }
-          {
-            checkConcept<GraphItemIt<_Graph, typename _Graph::Node>,
-              typename _Graph::ANodeIt >();
-            checkConcept<GraphItemIt<_Graph, typename _Graph::Node>,
-              typename _Graph::BNodeIt >();
-          }
-
-	}
-	
-	const _Graph& graph;
-	
-      };
-    };
-
-    /// \brief An empty alteration notifier graph class.
-    ///  
-    /// This class provides beside the core graph features alteration
-    /// notifier interface for the graph structure.  This implements
-    /// an observer-notifier pattern for each graph item. More
-    /// obsevers can be registered into the notifier and whenever an
-    /// alteration occured in the graph all the observers will
-    /// notified about it.
-    template <typename _Base = BaseGraphComponent>
-    class AlterableGraphComponent : public _Base {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-      typedef typename Base::Edge Edge;
-
-
-      /// The node observer registry.
-      typedef AlterationNotifier<AlterableGraphComponent, Node> 
-      NodeNotifier;
-      /// The edge observer registry.
-      typedef AlterationNotifier<AlterableGraphComponent, Edge> 
-      EdgeNotifier;
-      
-      /// \brief Gives back the node alteration notifier.
-      ///
-      /// Gives back the node alteration notifier.
-      NodeNotifier& getNotifier(Node) const {
-	return NodeNotifier();
-      }
-      
-      /// \brief Gives back the edge alteration notifier.
-      ///
-      /// Gives back the edge alteration notifier.
-      EdgeNotifier& getNotifier(Edge) const {
-	return EdgeNotifier();
-      }
-
-      template <typename _Graph> 
-      struct Constraints {
-	void constraints() {
-	  checkConcept<Base, _Graph>();
-          typename _Graph::NodeNotifier& nn 
-            = graph.getNotifier(typename _Graph::Node());
-
-          typename _Graph::EdgeNotifier& en 
-            = graph.getNotifier(typename _Graph::Edge());
-          
-          ignore_unused_variable_warning(nn);
-          ignore_unused_variable_warning(en);
-	}
-	
-	const _Graph& graph;
-	
-      };
-      
-    };
-
-    /// \brief An empty alteration notifier undirected graph class.
-    ///  
-    /// This class provides beside the core graph features alteration
-    /// notifier interface for the graph structure.  This implements
-    /// an observer-notifier pattern for each graph item. More
-    /// obsevers can be registered into the notifier and whenever an
-    /// alteration occured in the graph all the observers will
-    /// notified about it.
-    template <typename _Base = BaseUGraphComponent>
-    class AlterableUGraphComponent : public AlterableGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::UEdge UEdge;
-
-
-      /// The edge observer registry.
-      typedef AlterationNotifier<AlterableUGraphComponent, UEdge> 
-      UEdgeNotifier;
-      
-      /// \brief Gives back the edge alteration notifier.
-      ///
-      /// Gives back the edge alteration notifier.
-      UEdgeNotifier& getNotifier(UEdge) const {
-	return UEdgeNotifier();
-      }
-
-      template <typename _Graph> 
-      struct Constraints {
-	void constraints() {
-	  checkConcept<AlterableGraphComponent<Base>, _Graph>();
-          typename _Graph::UEdgeNotifier& uen 
-            = graph.getNotifier(typename _Graph::UEdge());
-          ignore_unused_variable_warning(uen);
-	}
-	
-	const _Graph& graph;
-	
-      };
-      
-    };
-
-    /// \brief An empty alteration notifier bipartite undirected graph
-    /// class.
-    ///  
-    /// This class provides beside the core graph features alteration
-    /// notifier interface for the graph structure.  This implements
-    /// an observer-notifier pattern for each graph item. More
-    /// obsevers can be registered into the notifier and whenever an
-    /// alteration occured in the graph all the observers will
-    /// notified about it.
-    template <typename _Base = BaseUGraphComponent>
-    class AlterableBpUGraphComponent : public AlterableUGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::ANode ANode;
-      typedef typename Base::BNode BNode;
-
-
-      /// The A-node observer registry.
-      typedef AlterationNotifier<AlterableBpUGraphComponent, ANode> 
-      ANodeNotifier;
-
-      /// The B-node observer registry.
-      typedef AlterationNotifier<AlterableBpUGraphComponent, BNode> 
-      BNodeNotifier;
-      
-      /// \brief Gives back the A-node alteration notifier.
-      ///
-      /// Gives back the A-node alteration notifier.
-      ANodeNotifier& getNotifier(ANode) const {
-	return ANodeNotifier();
-      }
-
-      /// \brief Gives back the B-node alteration notifier.
-      ///
-      /// Gives back the B-node alteration notifier.
-      BNodeNotifier& getNotifier(BNode) const {
-	return BNodeNotifier();
-      }
-
-      template <typename _Graph> 
-      struct Constraints {
-	void constraints() {
-          checkConcept<AlterableUGraphComponent<Base>, _Graph>();
-          typename _Graph::ANodeNotifier& ann 
-            = graph.getNotifier(typename _Graph::ANode());
-          typename _Graph::BNodeNotifier& bnn 
-            = graph.getNotifier(typename _Graph::BNode());
-          ignore_unused_variable_warning(ann);
-          ignore_unused_variable_warning(bnn);
-	}
-	
-	const _Graph& graph;
-	
-      };
-      
-    };
-
-
-    /// \brief Class describing the concept of graph maps
-    /// 
-    /// This class describes the common interface of the graph maps
-    /// (NodeMap, EdgeMap), that is \ref maps-page "maps" which can be used to
-    /// associate data to graph descriptors (nodes or edges).
-    template <typename _Graph, typename _Item, typename _Value>
-    class GraphMap : public ReadWriteMap<_Item, _Value> {
-    public:
-
-      typedef ReadWriteMap<_Item, _Value> Parent;
-
-      /// The graph type of the map.
-      typedef _Graph Graph;
-      /// The key type of the map.
-      typedef _Item Key;
-      /// The value type of the map.
-      typedef _Value Value;
-
-      /// \brief Construct a new map.
-      ///
-      /// Construct a new map for the graph.
-      explicit GraphMap(const Graph&) {}
-      /// \brief Construct a new map with default value.
-      ///
-      /// Construct a new map for the graph and initalise the values.
-      GraphMap(const Graph&, const Value&) {}
-      /// \brief Copy constructor.
-      ///
-      /// Copy Constructor.
-      GraphMap(const GraphMap&) : Parent() {}
-      
-      /// \brief Assign operator.
-      ///
-      /// Assign operator. It does not mofify the underlying graph,
-      /// it just iterates on the current item set and set the  map
-      /// with the value returned by the assigned map. 
-      template <typename CMap>
-      GraphMap& operator=(const CMap&) { 
-        checkConcept<ReadMap<Key, Value>, CMap>();
-        return *this;
-      }
-
-      template<typename _Map>
-      struct Constraints {
-	void constraints() {
-	  checkConcept<ReadWriteMap<Key, Value>, _Map >();
-	  // Construction with a graph parameter
-	  _Map a(g);
-	  // Constructor with a graph and a default value parameter
-	  _Map a2(g,t);
-	  // Copy constructor.
-	  _Map b(c);
-          
-          ReadMap<Key, Value> cmap;
-          b = cmap;
-
-	  ignore_unused_variable_warning(a2);
-	  ignore_unused_variable_warning(b);
-	}
-
-	const _Map &c;
-	const Graph &g;
-	const typename GraphMap::Value &t;
-      };
-
-    };
-
-    /// \brief An empty mappable graph class.
-    ///
-    /// This class provides beside the core graph features
-    /// map interface for the graph structure.
-    /// This concept is part of the Graph concept.
-    template <typename _Base = BaseGraphComponent>
-    class MappableGraphComponent : public _Base  {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-      typedef typename Base::Edge Edge;
-
-      typedef MappableGraphComponent Graph;
-
-      /// \brief ReadWrite map of the nodes.
-      ///
-      /// ReadWrite map of the nodes.
-      ///
-      template <typename _Value>
-      class NodeMap : public GraphMap<Graph, Node, _Value> {
-      private:
-	NodeMap();
-      public:
-        typedef GraphMap<MappableGraphComponent, Node, _Value> Parent;
-
-	/// \brief Construct a new map.
-	///
-	/// Construct a new map for the graph.
-	/// \todo call the right parent class constructor
-	explicit NodeMap(const MappableGraphComponent& graph) 
-          : Parent(graph) {}
-
-	/// \brief Construct a new map with default value.
-	///
-	/// Construct a new map for the graph and initalise the values.
-	NodeMap(const MappableGraphComponent& graph, const _Value& value)
-          : Parent(graph, value) {}
-
-	/// \brief Copy constructor.
-	///
-	/// Copy Constructor.
-	NodeMap(const NodeMap& nm) : Parent(nm) {}
-
-	/// \brief Assign operator.
-	///
-	/// Assign operator.
-        template <typename CMap>
-        NodeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Node, _Value>, CMap>();
-          return *this;
-        }
-
-      };
-
-      /// \brief ReadWrite map of the edges.
-      ///
-      /// ReadWrite map of the edges.
-      ///
-      template <typename _Value>
-      class EdgeMap : public GraphMap<Graph, Edge, _Value> {
-      private:
-	EdgeMap();
-      public:
-        typedef GraphMap<MappableGraphComponent, Edge, _Value> Parent;
-
-	/// \brief Construct a new map.
-	///
-	/// Construct a new map for the graph.
-	/// \todo call the right parent class constructor
-	explicit EdgeMap(const MappableGraphComponent& graph) 
-          : Parent(graph) {}
-
-	/// \brief Construct a new map with default value.
-	///
-	/// Construct a new map for the graph and initalise the values.
-	EdgeMap(const MappableGraphComponent& graph, const _Value& value)
-          : Parent(graph, value) {}
-
-	/// \brief Copy constructor.
-	///
-	/// Copy Constructor.
-	EdgeMap(const EdgeMap& nm) : Parent(nm) {}
-
-	/// \brief Assign operator.
-	///
-	/// Assign operator.
-        template <typename CMap>
-        EdgeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Edge, _Value>, CMap>();
-          return *this;
-        }
-
-      };
-
-
-      template <typename _Graph>
-      struct Constraints {
-
-	struct Dummy {
-	  int value;
-	  Dummy() : value(0) {}
-	  Dummy(int _v) : value(_v) {}
-	};
-
-	void constraints() {
-	  checkConcept<Base, _Graph>();
-	  { // int map test
-	    typedef typename _Graph::template NodeMap<int> IntNodeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::Node, int>, 
-	      IntNodeMap >();
-	  } { // bool map test
-	    typedef typename _Graph::template NodeMap<bool> BoolNodeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::Node, bool>,
-	      BoolNodeMap >();
-	  } { // Dummy map test
-	    typedef typename _Graph::template NodeMap<Dummy> DummyNodeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::Node, Dummy>,
-	      DummyNodeMap >();
-	  } 
-
-	  { // int map test
-	    typedef typename _Graph::template EdgeMap<int> IntEdgeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, int>,
-	      IntEdgeMap >();
-	  } { // bool map test
-	    typedef typename _Graph::template EdgeMap<bool> BoolEdgeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, bool>,
-	      BoolEdgeMap >();
-	  } { // Dummy map test
-	    typedef typename _Graph::template EdgeMap<Dummy> DummyEdgeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, Dummy>, 
-	      DummyEdgeMap >();
-	  } 
-	}
-
-	_Graph& graph;
-      };
-    };
-
-    /// \brief An empty mappable base bipartite undirected graph class.
-    ///
-    /// This class provides beside the core graph features
-    /// map interface for the graph structure.
-    /// This concept is part of the UGraph concept.
-    template <typename _Base = BaseUGraphComponent>
-    class MappableUGraphComponent : public MappableGraphComponent<_Base>  {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::UEdge UEdge;
-
-      typedef MappableUGraphComponent Graph;
-
-      /// \brief ReadWrite map of the uedges.
-      ///
-      /// ReadWrite map of the uedges.
-      ///
-      template <typename _Value>
-      class UEdgeMap : public GraphMap<Graph, UEdge, _Value> {  
-      public:
-        typedef GraphMap<MappableUGraphComponent, UEdge, _Value> Parent;
-
-	/// \brief Construct a new map.
-	///
-	/// Construct a new map for the graph.
-	/// \todo call the right parent class constructor
-	explicit UEdgeMap(const MappableUGraphComponent& graph) 
-          : Parent(graph) {}
-
-	/// \brief Construct a new map with default value.
-	///
-	/// Construct a new map for the graph and initalise the values.
-	UEdgeMap(const MappableUGraphComponent& graph, const _Value& value)
-          : Parent(graph, value) {}
-
-	/// \brief Copy constructor.
-	///
-	/// Copy Constructor.
-	UEdgeMap(const UEdgeMap& nm) : Parent(nm) {}
-
-	/// \brief Assign operator.
-	///
-	/// Assign operator.
-        template <typename CMap>
-        UEdgeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<UEdge, _Value>, CMap>();
-          return *this;
-        }
-
-      };
-
-
-      template <typename _Graph>
-      struct Constraints {
-
-	struct Dummy {
-	  int value;
-	  Dummy() : value(0) {}
-	  Dummy(int _v) : value(_v) {}
-	};
-
-	void constraints() {
-	  checkConcept<MappableGraphComponent<Base>, _Graph>();
-
-	  { // int map test
-	    typedef typename _Graph::template UEdgeMap<int> IntUEdgeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, int>,
-	      IntUEdgeMap >();
-	  } { // bool map test
-	    typedef typename _Graph::template UEdgeMap<bool> BoolUEdgeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, bool>,
-	      BoolUEdgeMap >();
-	  } { // Dummy map test
-	    typedef typename _Graph::template UEdgeMap<Dummy> DummyUEdgeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, Dummy>, 
-	      DummyUEdgeMap >();
-	  } 
-	}
-
-	_Graph& graph;
-      };
-    };
-
-    /// \brief An empty mappable base bipartite undirected graph
-    /// class.
-    ///
-    /// This class provides beside the core graph features
-    /// map interface for the graph structure.
-    /// This concept is part of the BpUGraph concept.
-    template <typename _Base = BaseBpUGraphComponent>
-    class MappableBpUGraphComponent : public MappableUGraphComponent<_Base>  {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-
-      typedef MappableBpUGraphComponent Graph;
-
-      /// \brief ReadWrite map of the A-nodes.
-      ///
-      /// ReadWrite map of the A-nodes.
-      ///
-      template <typename _Value>
-      class ANodeMap : public GraphMap<Graph, Node, _Value> {  
-      public:
-        typedef GraphMap<MappableBpUGraphComponent, Node, _Value> Parent;
-
-	/// \brief Construct a new map.
-	///
-	/// Construct a new map for the graph.
-	/// \todo call the right parent class constructor
-	explicit ANodeMap(const MappableBpUGraphComponent& graph) 
-          : Parent(graph) {}
-
-	/// \brief Construct a new map with default value.
-	///
-	/// Construct a new map for the graph and initalise the values.
-	ANodeMap(const MappableBpUGraphComponent& graph, const _Value& value)
-          : Parent(graph, value) {}
-
-	/// \brief Copy constructor.
-	///
-	/// Copy Constructor.
-	ANodeMap(const ANodeMap& nm) : Parent(nm) {}
-
-	/// \brief Assign operator.
-	///
-	/// Assign operator.
-        template <typename CMap>
-        ANodeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Node, _Value>, CMap>();
-          return *this;
-        }
-
-      };
-
-      /// \brief ReadWrite map of the B-nodes.
-      ///
-      /// ReadWrite map of the A-nodes.
-      ///
-      template <typename _Value>
-      class BNodeMap : public GraphMap<Graph, Node, _Value> {  
-      public:
-        typedef GraphMap<MappableBpUGraphComponent, Node, _Value> Parent;
-
-	/// \brief Construct a new map.
-	///
-	/// Construct a new map for the graph.
-	/// \todo call the right parent class constructor
-	explicit BNodeMap(const MappableBpUGraphComponent& graph) 
-          : Parent(graph) {}
-
-	/// \brief Construct a new map with default value.
-	///
-	/// Construct a new map for the graph and initalise the values.
-	BNodeMap(const MappableBpUGraphComponent& graph, const _Value& value)
-          : Parent(graph, value) {}
-
-	/// \brief Copy constructor.
-	///
-	/// Copy Constructor.
-	BNodeMap(const BNodeMap& nm) : Parent(nm) {}
-
-	/// \brief Assign operator.
-	///
-	/// Assign operator.
-        template <typename CMap>
-        BNodeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Node, _Value>, CMap>();
-          return *this;
-        }
-
-      };
-
-
-      template <typename _Graph>
-      struct Constraints {
-
-	struct Dummy {
-	  int value;
-	  Dummy() : value(0) {}
-	  Dummy(int _v) : value(_v) {}
-	};
-
-	void constraints() {
-	  checkConcept<MappableUGraphComponent<Base>, _Graph>();
-
-	  { // int map test
-	    typedef typename _Graph::template ANodeMap<int> IntANodeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::ANode, int>,
-	      IntANodeMap >();
-	  } { // bool map test
-	    typedef typename _Graph::template ANodeMap<bool> BoolANodeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::ANode, bool>,
-	      BoolANodeMap >();
-	  } { // Dummy map test
-	    typedef typename _Graph::template ANodeMap<Dummy> DummyANodeMap;
-	    checkConcept<GraphMap<_Graph, typename _Graph::ANode, Dummy>, 
-	      DummyANodeMap >();
-	  } 
-	}
-
-	_Graph& graph;
-      };
-    };
-
-
-    /// \brief An empty extendable graph class.
-    ///
-    /// This class provides beside the core graph features graph
-    /// extendable interface for the graph structure.  The main
-    /// difference between the base and this interface is that the
-    /// graph alterations should handled already on this level.
-    template <typename _Base = BaseGraphComponent>
-    class ExtendableGraphComponent : public _Base {
-    public:
-      typedef _Base Base;
-
-      typedef typename _Base::Node Node;
-      typedef typename _Base::Edge Edge;
-
-      /// \brief Adds a new node to the graph.
-      ///
-      /// Adds a new node to the graph.
-      ///
-      Node addNode() {
-	return INVALID;
-      }
-    
-      /// \brief Adds a new edge connects the given two nodes.
-      ///
-      /// Adds a new edge connects the the given two nodes.
-      Edge addEdge(const Node&, const Node&) {
-	return INVALID;
-      }
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-          checkConcept<Base, _Graph>();
-	  typename _Graph::Node node_a, node_b;
-	  node_a = graph.addNode();
-	  node_b = graph.addNode();
-	  typename _Graph::Edge edge;
-	  edge = graph.addEdge(node_a, node_b);
-	}
-
-	_Graph& graph;
-      };
-    };
-
-    /// \brief An empty extendable base undirected graph class.
-    ///
-    /// This class provides beside the core undirected graph features
-    /// core undircted graph extend interface for the graph structure.
-    /// The main difference between the base and this interface is
-    /// that the graph alterations should handled already on this
-    /// level.
-    template <typename _Base = BaseUGraphComponent>
-    class ExtendableUGraphComponent : public _Base {
-    public:
-
-      typedef _Base Base;
-      typedef typename _Base::Node Node;
-      typedef typename _Base::UEdge UEdge;
-
-      /// \brief Adds a new node to the graph.
-      ///
-      /// Adds a new node to the graph.
-      ///
-      Node addNode() {
-	return INVALID;
-      }
-    
-      /// \brief Adds a new edge connects the given two nodes.
-      ///
-      /// Adds a new edge connects the the given two nodes.
-      UEdge addEdge(const Node&, const Node&) {
-	return INVALID;
-      }
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-	  checkConcept<Base, _Graph>();
-	  typename _Graph::Node node_a, node_b;
-	  node_a = graph.addNode();
-	  node_b = graph.addNode();
-	  typename _Graph::UEdge uedge;
-	  uedge = graph.addUEdge(node_a, node_b);
-	}
-
-	_Graph& graph;
-      };
-    };
-
-    /// \brief An empty extendable base undirected graph class.
-    ///
-    /// This class provides beside the core bipartite undirected graph
-    /// features core undircted graph extend interface for the graph
-    /// structure.  The main difference between the base and this
-    /// interface is that the graph alterations should handled already
-    /// on this level.
-    template <typename _Base = BaseBpUGraphComponent>
-    class ExtendableBpUGraphComponent 
-      : public ExtendableUGraphComponent<_Base> {
-
-      typedef _Base Base;
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-          checkConcept<ExtendableUGraphComponent<Base>, _Graph>();
-	}
-      };
-    };
-
-    /// \brief An empty erasable graph class.
-    ///  
-    /// This class provides beside the core graph features core erase
-    /// functions for the graph structure. The main difference between
-    /// the base and this interface is that the graph alterations
-    /// should handled already on this level.
-    template <typename _Base = BaseGraphComponent>
-    class ErasableGraphComponent : public _Base {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-      typedef typename Base::Edge Edge;
-
-      /// \brief Erase a node from the graph.
-      ///
-      /// Erase a node from the graph. This function should 
-      /// erase all edges connecting to the node.
-      void erase(const Node&) {}    
-
-      /// \brief Erase an edge from the graph.
-      ///
-      /// Erase an edge from the graph.
-      ///
-      void erase(const Edge&) {}
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-          checkConcept<Base, _Graph>();
-	  typename _Graph::Node node;
-	  graph.erase(node);
-	  typename _Graph::Edge edge;
-	  graph.erase(edge);
-	}
-
-	_Graph& graph;
-      };
-    };
-
-    /// \brief An empty erasable base undirected graph class.
-    ///  
-    /// This class provides beside the core undirected graph features
-    /// core erase functions for the undirceted graph structure. The
-    /// main difference between the base and this interface is that
-    /// the graph alterations should handled already on this level.
-    template <typename _Base = BaseUGraphComponent>
-    class ErasableUGraphComponent : public _Base {
-    public:
-
-      typedef _Base Base;
-      typedef typename Base::Node Node;
-      typedef typename Base::UEdge UEdge;
-
-      /// \brief Erase a node from the graph.
-      ///
-      /// Erase a node from the graph. This function should erase
-      /// edges connecting to the node.
-      void erase(const Node&) {}    
-
-      /// \brief Erase an edge from the graph.
-      ///
-      /// Erase an edge from the graph.
-      ///
-      void erase(const UEdge&) {}
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-          checkConcept<Base, _Graph>();
-	  typename _Graph::Node node;
-	  graph.erase(node);
-	  typename _Graph::Edge edge;
-	  graph.erase(edge);
-	}
-
-	_Graph& graph;
-      };
-    };
-
-    /// \brief An empty erasable base bipartite undirected graph class.
-    ///  
-    /// This class provides beside the core bipartite undirected graph
-    /// features core erase functions for the undirceted graph
-    /// structure. The main difference between the base and this
-    /// interface is that the graph alterations should handled already
-    /// on this level.
-    template <typename _Base = BaseBpUGraphComponent>
-    class ErasableBpUGraphComponent : public ErasableUGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-          checkConcept<ErasableUGraphComponent<Base>, _Graph>();
-	}
-      };
-    };
-
-    /// \brief An empty clearable base graph class.
-    ///
-    /// This class provides beside the core graph features core clear
-    /// functions for the graph structure. The main difference between
-    /// the base and this interface is that the graph alterations
-    /// should handled already on this level.
-    template <typename _Base = BaseGraphComponent>
-    class ClearableGraphComponent : public _Base {
-    public:
-
-      typedef _Base Base;
-
-      /// \brief Erase all nodes and edges from the graph.
-      ///
-      /// Erase all nodes and edges from the graph.
-      ///
-      void clear() {}    
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-          checkConcept<Base, _Graph>();
-	  graph.clear();
-	}
-
-	_Graph graph;
-      };
-    };
-
-    /// \brief An empty clearable base undirected graph class.
-    ///
-    /// This class provides beside the core undirected graph features
-    /// core clear functions for the undirected graph structure. The
-    /// main difference between the base and this interface is that
-    /// the graph alterations should handled already on this level.
-    template <typename _Base = BaseUGraphComponent>
-    class ClearableUGraphComponent : public ClearableUGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-          checkConcept<ClearableUGraphComponent<Base>, _Graph>();
-	}
-
-	_Graph graph;
-      };
-    };
-
-    /// \brief An empty clearable base bipartite undirected graph
-    /// class.
-    ///
-    /// This class provides beside the core bipartite undirected graph
-    /// features core clear functions for the undirected graph
-    /// structure. The main difference between the base and this
-    /// interface is that the graph alterations should handled already
-    /// on this level.
-    template <typename _Base = BaseUGraphComponent>
-    class ClearableBpUGraphComponent 
-      : public ClearableBpUGraphComponent<_Base> {
-    public:
-
-      typedef _Base Base;
-
-      template <typename _Graph>
-      struct Constraints {
-	void constraints() {
-          checkConcept<ClearableBpUGraphComponent<Base>, _Graph>();
-	}
-
-      };
-
-    };
-
-  }
-
-}
-
-#endif
Index: lemon/concept/heap.h
===================================================================
--- lemon/concept/heap.h	(revision 1993)
+++ 	(revision )
@@ -1,223 +1,0 @@
-/* -*- C++ -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library
- *
- * Copyright (C) 2003-2006
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-///\ingroup concept
-///\file
-///\brief Classes for representing heaps.
-///
-
-#ifndef LEMON_CONCEPT_HEAP_H
-#define LEMON_CONCEPT_HEAP_H
-
-#include <lemon/bits/invalid.h>
-
-namespace lemon {
-  namespace concept {
-    /// \addtogroup concept
-    /// @{
-
-
-    /// \brief A concept structure describes the main interface of heaps.
-    ///
-    /// A concept structure describes the main interface of heaps.
-    ///
-    template <typename Item, typename Prio, typename ItemIntMap>
-    class Heap {
-    public:
-  
-
-      /// \brief Type to represent the items states.
-      ///
-      /// Each Item element have a state associated to it. It may be "in heap",
-      /// "pre heap" or "post heap". The later two are indifferent from the
-      /// heap's point of view, but may be useful to the user.
-      ///
-      /// The ItemIntMap _should_ be initialized in such way, that it maps
-      /// PRE_HEAP (-1) to any element to be put in the heap...
-      enum state_enum {
-	IN_HEAP = 0,
-	PRE_HEAP = -1,
-	POST_HEAP = -2
-      };
-      
-      /// \brief The constructor.
-      ///
-      /// The constructor.
-      /// \param _iim should be given to the constructor, since it is used
-      /// internally to handle the cross references. The value of the map
-      /// should be PRE_HEAP (-1) for each element.
-      explicit Heap(ItemIntMap &_iim) {}
-
-      /// \brief The number of items stored in the heap.
-      ///
-      /// Returns the number of items stored in the heap.
-      int size() const { return 0; }
-
-      /// \brief Checks if the heap stores no items.
-      ///
-      /// Returns \c true if and only if the heap stores no items.
-      bool empty() const { return false; }
-
-      /// \brief Makes empty this heap.
-      ///
-      /// Makes this heap empty.
-      void clear();
-
-      /// \brief Insert an item into the heap with the given heap.
-      ///    
-      /// Adds \c i to the heap with priority \c p. 
-      /// \param i The item to insert.
-      /// \param p The priority of the item.
-      void push(const Item &i, const Prio &p) {}
-
-      /// \brief Returns the item with minimum priority.
-      ///
-      /// This method returns the item with minimum priority.  
-      /// \pre The heap must be nonempty.  
-      Item top() const {}
-
-      /// \brief Returns the minimum priority.
-      ///
-      /// It returns the minimum priority.
-      /// \pre The heap must be nonempty.
-      Prio prio() const {}
-
-      /// \brief Deletes the item with minimum priority.
-      ///
-      /// This method deletes the item with minimum priority.
-      /// \pre The heap must be non-empty.  
-      void pop() {}
-
-      /// \brief Deletes \c i from the heap.
-      ///
-      /// This method deletes item \c i from the heap, if \c i was
-      /// already stored in the heap.
-      /// \param i The item to erase. 
-      void erase(const Item &i) {}
-
-      /// \brief Returns the priority of \c i.
-      ///
-      /// This function returns the priority of item \c i.  
-      /// \pre \c i must be in the heap.
-      /// \param i The item.
-      Prio operator[](const Item &i) const {}
-
-      /// \brief \c i gets to the heap with priority \c p independently 
-      /// if \c i was already there.
-      ///
-      /// This method calls \ref push(\c i, \c p) if \c i is not stored
-      /// in the heap and sets the priority of \c i to \c p otherwise.
-      /// It may throw an \e UnderFlowPriorityException. 
-      /// \param i The item.
-      /// \param p The priority.
-      void set(const Item &i, const Prio &p) {}
-      
-      /// \brief Decreases the priority of \c i to \c p.
-      ///
-      /// This method decreases the priority of item \c i to \c p.
-      /// \pre \c i must be stored in the heap with priority at least \c p.
-      /// \param i The item.
-      /// \param p The priority.
-      void decrease(const Item &i, const Prio &p) {}
-
-      /// \brief Increases the priority of \c i to \c p.
-      ///
-      /// This method sets the priority of item \c i to \c p. 
-      /// \pre \c i must be stored in the heap with priority at most \c
-      /// p relative to \c Compare.
-      /// \param i The item.
-      /// \param p The priority.
-      void increase(const Item &i, const Prio &p) {}
-
-      /// \brief Returns if \c item is in, has already been in, or has 
-      /// never been in the heap.
-      ///
-      /// This method returns PRE_HEAP if \c item has never been in the
-      /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
-      /// otherwise. In the latter case it is possible that \c item will
-      /// get back to the heap again.
-      /// \param i The item.
-      state_enum state(const Item &i) const {}
-
-      /// \brief Sets the state of the \c item in the heap.
-      ///
-      /// Sets the state of the \c item in the heap. It can be used to
-      /// manually clear the heap when it is important to achive the
-      /// better time complexity.
-      /// \param i The item.
-      /// \param st The state. It should not be \c IN_HEAP. 
-      void state(const Item& i, state_enum st) {}
-
-
-      template <typename _Heap>
-      struct Constraints {
-      public:
-    
-	void constraints() {
-	  Item item;
-	  Prio prio;
-
-	  item=Item();
-	  prio=Prio();
-
-	  ignore_unused_variable_warning(item);
-	  ignore_unused_variable_warning(prio);
-
-	  typedef typename _Heap::state_enum state_enum;
-	  state_enum state;
-
-	  ignore_unused_variable_warning(state);
-      
-	  _Heap heap1 = _Heap(map);
-
-	  ignore_unused_variable_warning(heap1);
-      
-	  heap.push(item, prio);
-
-	  prio = heap.prio();
-	  item = heap.top();
-
-	  heap.pop();
-
-	  heap.set(item, prio);
-	  heap.decrease(item, prio);
-	  heap.increase(item, prio);
-	  prio = heap[item];
-
-	  heap.erase(item);
-
-	  state = heap.state(item);
-
-	  state = _Heap::PRE_HEAP;
-	  state = _Heap::IN_HEAP;
-	  state = _Heap::POST_HEAP;
-
-	  heap.clear();
-	}
-    
-	_Heap& heap;
-	ItemIntMap& map;
-
-	Constraints() : heap(0), map(0) {}
-      };
-    };
-
-    /// @}
-  } // namespace lemon
-}
-#endif // LEMON_CONCEPT_PATH_H
Index: lemon/concept/maps.h
===================================================================
--- lemon/concept/maps.h	(revision 1993)
+++ 	(revision )
@@ -1,192 +1,0 @@
-/* -*- C++ -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library
- *
- * Copyright (C) 2003-2006
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-#ifndef LEMON_CONCEPT_MAPS_H
-#define LEMON_CONCEPT_MAPS_H
-
-#include <lemon/bits/utility.h>
-#include <lemon/concept_check.h>
-
-///\ingroup concept
-///\file
-///\brief Map concepts checking classes for testing and documenting.
-
-namespace lemon {
-
-  namespace concept {
-  
-    /// \addtogroup concept
-    /// @{
-
-    /// Readable map concept
-    template<typename K, typename T>
-    class ReadMap
-    {
-    public:
-      /// Map's key type.
-      typedef K Key;    
-      /// Map's value type. (The type of objects associated with the keys).
-      typedef T Value;
-
-      // \bug Value don't need to be default constructible.
-      /// Returns the value associated with a key.
-      Value operator[](const Key &) const {return Value();}
-
-      template<typename _ReadMap>
-      struct Constraints {
-
-	void constraints() {
-	  Value val = m[key];
-	  val = m[key];
-	  typename _ReadMap::Value own_val = m[own_key]; 
-	  own_val = m[own_key]; 
-
-	  ignore_unused_variable_warning(val);
-	  ignore_unused_variable_warning(own_val);
-	  ignore_unused_variable_warning(key);
-	}
-	Key& key;
-	typename _ReadMap::Key& own_key;
-	_ReadMap& m;
-      };
-      
-    };
-
-
-    /// Writable map concept
-    template<typename K, typename T>
-    class WriteMap
-    {
-    public:
-      /// Map's key type.
-      typedef K Key;    
-      /// Map's value type. (The type of objects associated with the keys).
-      typedef T Value;
-
-      /// Sets the value associated with a key.
-      void set(const Key &,const Value &) {}
-
-      ///Default constructor
-      WriteMap() {}
-
-      template <typename _WriteMap>
-      struct Constraints {
-	void constraints() {
-	  // No constraints for constructor.
-	  m.set(key, val);
-	  m.set(own_key, own_val);
-	  ignore_unused_variable_warning(key);
-	  ignore_unused_variable_warning(val);
-	  ignore_unused_variable_warning(own_key);
-	  ignore_unused_variable_warning(own_val);
-	}
-
-	Value& val;
-	typename _WriteMap::Value own_val;
-	Key& key;
-	typename _WriteMap::Key& own_key;
-	_WriteMap& m;
-
-      };
-    };
-
-    ///Read/Writable map concept
-    template<typename K, typename T>
-    class ReadWriteMap : public ReadMap<K,T>,
-			    public WriteMap<K,T>
-    {
-    public:
-      /// Map's key type.
-      typedef K Key;    
-      /// Map's value type. (The type of objects associated with the keys).
-      typedef T Value;
-
-      /// Returns the value associated with a key.
-      Value operator[](const Key &) const {return Value();}
-      /// Sets the value associated with a key.
-      void set(const Key & ,const Value &) {}
-
-      template<typename _ReadWriteMap>
-      struct Constraints {
-	void constraints() {
-	  checkConcept<ReadMap<K, T>, _ReadWriteMap >();
-	  checkConcept<WriteMap<K, T>, _ReadWriteMap >();
-	}
-      };
-    };
-  
-  
-    ///Dereferable map concept
-    template<typename K, typename T, typename R, typename CR>
-    class ReferenceMap : public ReadWriteMap<K,T>
-    {
-    public:
-      /// Tag for reference maps.
-      typedef True ReferenceMapTag;
-      /// Map's key type.
-      typedef K Key;    
-      /// Map's value type. (The type of objects associated with the keys).
-      typedef T Value;
-      /// Map's reference type.
-      typedef R Reference;
-      /// Map's const reference type.
-      typedef CR ConstReference;
-
-    protected:
-      Value tmp;
-    public:
-
-      ///Returns a reference to the value associated to a key.
-      Reference operator[](const Key &) { return tmp; }
-      ///Returns a const reference to the value associated to a key.
-      ConstReference operator[](const Key &) const
-      { return tmp; }
-      /// Sets the value associated with a key.
-      void set(const Key &k,const Value &t) { operator[](k)=t; }
-
-      // \todo rethink this concept
-      template<typename _ReferenceMap>
-      struct ReferenceMapConcept {
-
-	void constraints() {
-	  checkConcept<ReadWriteMap, _ReferenceMap >();
-	  m[key] = val;
-	  val  = m[key];
-	  m[key] = ref;
-	  ref = m[key];
-	  m[own_key] = own_val;
-	  own_val  = m[own_key];
-	  m[own_key] = own_ref;
-	  own_ref = m[own_key];	  	  
-	}
-
-	typename _ReferenceMap::Key& own_key;
-	typename _ReferenceMap::Value& own_val;
-	typename _ReferenceMap::Reference& own_ref;
-	Key& key;
-	Value& val;
-	Reference& ref;
-	_ReferenceMap& m;
-      };
-    };
-
-    // @}
-
-  } //namespace concept
-} //namespace lemon
-#endif // LEMON_CONCEPT_MAPS_H
Index: lemon/concept/matrix_maps.h
===================================================================
--- lemon/concept/matrix_maps.h	(revision 1993)
+++ 	(revision )
@@ -1,207 +1,0 @@
-/* -*- C++ -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library
- *
- * Copyright (C) 2003-2006
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-#ifndef LEMON_CONCEPT_MATRIX_MAPS_H
-#define LEMON_CONCEPT_MATRIX_MAPS_H
-
-#include <lemon/bits/utility.h>
-#include <lemon/concept_check.h>
-
-///\ingroup concept
-///\file
-///\brief MatrixMap concepts checking classes for testing and documenting.
-
-namespace lemon {
-
-  namespace concept {
-  
-    /// \addtogroup concept
-    /// @{
-
-    /// Readable matrix map concept
-    template <typename K1, typename K2, typename V>
-    class ReadMatrixMap
-    {
-    public:
-      /// Map's first key type.
-      typedef K1 FirstKey;    
-      /// Map's second key type.
-      typedef K2 SecondKey;    
-      /// \brief Map's value type. 
-      /// (The type of objects associated with the pairs of keys).
-      typedef V Value;
-
-      // \bug Value don't need to be default constructible.
-      /// Returns the value associated with a key.
-      Value operator()(const FirstKey&, const SecondKey&) const {
-	return Value();
-      }
-
-      template <typename _ReadMatrixMap>
-      struct Constraints {
-
-	void constraints() {
-	  Value val = m(first_key, second_key);
-	  val = m(first_key, second_key);
-	  typename _ReadMatrixMap::Value own_val = 
-	    m(own_first_key, own_second_key); 
-	  own_val = m(own_first_key, own_second_key);
-	  ignore_unused_variable_warning(val);
-	  ignore_unused_variable_warning(own_val);
-	}
-
-	FirstKey& first_key;
-	SecondKey& second_key;	
-	typename _ReadMatrixMap::FirstKey& own_first_key;
-	typename _ReadMatrixMap::SecondKey& own_second_key;
-	_ReadMatrixMap& m;
-      };
-      
-    };
-
-
-    /// Writable map concept
-    template <typename K1, typename K2, typename V>
-    class WriteMatrixMap {
-    public:
-      /// Map's first key type.
-      typedef K1 FirstKey;    
-      /// Map's second key type.
-      typedef K2 SecondKey;    
-      /// \brief Map's value type. 
-      /// (The type of objects associated with the pairs of keys).
-      typedef V Value;
-
-      /// Sets the value associated with the pair of keys.
-      void set(const FirstKey&, const SecondKey& ,const Value&) {}
-
-      template <typename _WriteMatrixMap>
-      struct Constraints {
-	void constraints() {
-	  // No constraints for constructor.
-	  m.set(first_key, second_key, val);
-	  m.set(own_first_key, own_second_key, own_val);
-	}
-
-	Value& val;
-	typename _WriteMatrixMap::Value own_val;
-	FirstKey& first_key;
-	SecondKey& second_key;
-	typename _WriteMatrixMap::FirstKey& own_first_key;
-	typename _WriteMatrixMap::SecondKey& own_second_key;
-	_WriteMatrixMap& m;
-
-      };
-    };
-
-    ///Read/Writable map concept
-    template<typename K1, typename K2, typename V>
-    class ReadWriteMatrixMap 
-      : public ReadMatrixMap<K1, K2, V>, public WriteMatrixMap<K1, K2, V> {
-    public:
-      /// Map's first key type.
-      typedef K1 FirstKey;    
-      /// Map's second key type.
-      typedef K2 SecondKey;    
-      /// \brief Map's value type. 
-      /// (The type of objects associated with the pairs of keys).
-      typedef V Value;
-
-      /// Returns the value associated with a pair of keys.
-      Value operator()(const FirstKey&, const SecondKey&) const { 
-	return Value(); 
-      }
-      /// Sets the value associated with the pair of keys.
-      void set(const FirstKey&, const SecondKey& ,const Value&) {}
-
-      template<typename _ReadWriteMatrixMap>
-      struct Constraints {
-	void constraints() {
-	  checkConcept<ReadMatrixMap<K1, K2, V>, _ReadWriteMatrixMap >();
-	  checkConcept<WriteMatrixMap<K1, K2, V>, _ReadWriteMatrixMap >();
-	}
-      };
-    };
-  
-  
-    ///Dereferable matrix map concept
-    template<typename K1, typename K2, typename V, typename R, typename CR>
-    class ReferenceMatrixMap : public ReadWriteMatrixMap<K1, K2, V>
-    {
-    public:
-      /// Tag for reference maps.
-      typedef True ReferenceMapTag;
-      /// Map's first key type.
-      typedef K1 FirstKey;    
-      /// Map's second key type.
-      typedef K1 SecondKey;    
-      /// Map's value type. (The type of objects associated with the keys).
-      typedef V Value;
-      /// Map's reference type.
-      typedef R Reference;
-      /// Map's const reference type.
-      typedef CR ConstReference;
-
-    protected:
-      Value tmp;
-    public:
-
-      ///Returns a reference to the value associated to a pair of keys.
-      Reference operator()(const FirstKey&, const SecondKey&) { 
-	return tmp; 
-      }
-      ///Returns a const reference to the value associated to a pair of keys.
-      ConstReference operator()(const FirstKey&, const SecondKey&) const { 
-	return tmp; 
-      }
-      /// Sets the value associated with the pair of keys.
-      void set(const FirstKey&, const SecondKey& ,const Value&) {}
-
-      // \todo rethink this concept
-      template<typename _ReferenceMatrixMap>
-      struct ReferenceMapConcept {
-
-	void constraints() {
-	  checkConcept<ReadWriteMatrixMap, _ReferenceMatrixMap >();
-	  m(first_key, second_key) = val;
-	  val  = m(first_key, second_key);
-	  m(first_key, second_key) = ref;
-	  ref = m(first_key, second_key);
-	  m(own_first_key, own_second_key) = own_val;
-	  own_val  = m(own_first_key, own_second_key);
-	  m(own_first_key, own_second_key) = own_ref;
-	  own_ref = m(own_first_key, own_second_key); 
-	}
-
-	typename _ReferenceMatrixMap::Key& own_first_key;
-	typename _ReferenceMatrixMap::Key& own_second_key;
-	typename _ReferenceMatrixMap::Value& own_val;
-	typename _ReferenceMatrixMap::Reference& own_ref;
-	FirstKey& first_key;
-	SecondKey& second_key;
-	Value& val;
-	Reference& ref;
-	_ReferenceMatrixMap& m;
-      };
-    };
-
-    // @}
-
-  } //namespace concept
-} //namespace lemon
-#endif // LEMON_CONCEPT_MATRIX_MAPS_H
Index: lemon/concept/path.h
===================================================================
--- lemon/concept/path.h	(revision 2247)
+++ 	(revision )
@@ -1,294 +1,0 @@
-/* -*- C++ -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library
- *
- * Copyright (C) 2003-2006
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-///\ingroup concept
-///\file
-///\brief Classes for representing paths in graphs.
-///
-///\todo Iterators have obsolete style
-
-#ifndef LEMON_CONCEPT_PATH_H
-#define LEMON_CONCEPT_PATH_H
-
-#include <lemon/bits/invalid.h>
-#include <lemon/concept_check.h>
-
-namespace lemon {
-  namespace concept {
-    /// \addtogroup concept
-    /// @{
-
-
-    //! \brief A skeleton structure for representing directed paths in a graph.
-    //!
-    //! A skeleton structure for representing directed paths in a graph.
-    //! \param _Graph The graph type in which the path is.
-    //!
-    //! In a sense, the path can be treated as a graph, for it has \c NodeIt
-    //! and \c EdgeIt with the same usage. These types converts to the \c Node
-    //! and \c Edge of the original graph.
-    template<typename _Graph>
-    class Path {
-    public:
-
-      /// Type of the underlying graph.
-      typedef _Graph Graph;
-      /// Edge type of the underlying graph.
-      typedef typename Graph::Edge Edge;
-      /// Node type of the underlying graph.
-      typedef typename Graph::Node Node;
-
-      class NodeIt;
-      class EdgeIt;
-
-      /// \param _g The graph in which the path is.
-      ///
-      Path(const Graph &_g) {
-	ignore_unused_variable_warning(_g);
-      }
-
-      /// Length of the path ie. the number of edges in the path.
-      int length() const {return 0;}
-
-      /// Returns whether the path is empty.
-      bool empty() const { return true;}
-
-      /// Resets the path to an empty path.
-      void clear() {}
-
-      /// \brief Starting point of the path.
-      ///
-      /// Starting point of the path.
-      /// Returns INVALID if the path is empty.
-      Node target() const {return INVALID;}
-      /// \brief End point of the path.
-      ///
-      /// End point of the path.
-      /// Returns INVALID if the path is empty.
-      Node source() const {return INVALID;}
-
-      /// \brief The target of an edge.
-      ///
-      /// Returns node iterator pointing to the target node of the
-      /// given edge iterator.
-      NodeIt target(const EdgeIt&) const {return INVALID;}
-
-      /// \brief The source of an edge.
-      ///
-      /// Returns node iterator pointing to the source node of the
-      /// given edge iterator.
-      NodeIt source(const EdgeIt&) const {return INVALID;}
-
-      /// \brief Iterator class to iterate on the nodes of the paths
-      ///
-      /// This class is used to iterate on the nodes of the paths
-      ///
-      /// Of course it converts to Graph::Node.
-      class NodeIt {
-      public:
-	/// Default constructor
-	NodeIt() {}
-	/// Invalid constructor
-	NodeIt(Invalid) {}
-	/// Constructor with starting point
-	NodeIt(const Path &) {}
-
-	///Conversion to Graph::Node
-	operator Node() const { return INVALID; }
-	/// Next node
-	NodeIt& operator++() {return *this;}
-
-	/// Comparison operator
-	bool operator==(const NodeIt&) const {return true;}
-	/// Comparison operator
-	bool operator!=(const NodeIt&) const {return true;}
- 	/// Comparison operator
- 	bool operator<(const NodeIt&) const {return false;}
-
-      };
-
-      /// \brief Iterator class to iterate on the edges of the paths
-      ///
-      /// This class is used to iterate on the edges of the paths
-      ///
-      /// Of course it converts to Graph::Edge
-      class EdgeIt {
-      public:
-	/// Default constructor
-	EdgeIt() {}
-	/// Invalid constructor
-	EdgeIt(Invalid) {}
-	/// Constructor with starting point
-	EdgeIt(const Path &) {}
-
-	operator Edge() const { return INVALID; }
-
-	/// Next edge
-	EdgeIt& operator++() {return *this;}
-
-	/// Comparison operator
-	bool operator==(const EdgeIt&) const {return true;}
-	/// Comparison operator
-	bool operator!=(const EdgeIt&) const {return true;}
- 	/// Comparison operator
- 	bool operator<(const EdgeIt&) const {return false;}
-
-      };
-
-
-      friend class Builder;
-
-      /// \brief Class to build paths
-      ///
-      /// This class is used to fill a path with edges.
-      ///
-      /// You can push new edges to the front and to the back of the path in
-      /// arbitrary order then you should commit these changes to the graph.
-      ///
-      /// While the builder is active (after the first modifying
-      /// operation and until the call of \ref commit()) the
-      /// underlining Path is in a "transitional" state (operations on
-      /// it have undefined result).
-      class Builder {
-      public:
-
-        /// Constructor
-
-        /// Constructor
-	/// \param _path the path you want to fill in.
-	///
-
-	Builder(Path &_path) { ignore_unused_variable_warning(_path); }
-
-	/// Sets the starting node of the path.
-
-	/// Sets the starting node of the path. Edge added to the path
-	/// afterwards have to be incident to this node.
-	/// You \em must start building an empty path with these functions.
-	/// (And you \em must \em not use it later).
-	/// \sa pushFront()
-	/// \sa pushBack()
-	void setStartNode(const Node &) {}
-
-	///Push a new edge to the front of the path
-
-	///Push a new edge to the front of the path.
-	///If the path is empty, you \em must call \ref setStartNode() before
-	///the first use of \ref pushFront().
-	void pushFront(const Edge&) {}
-
-	///Push a new edge to the back of the path
-
-	///Push a new edge to the back of the path.
-	///If the path is empty, you \em must call \ref setStartNode() before
-	///the first use of \ref pushBack().
-	void pushBack(const Edge&) {}
-
-	///Commit the changes to the path.
-
-	///Commit the changes to the path.
-        ///
-	void commit() {}
-
-	///Reserve (front) storage for the builder in advance.
-
-	///If you know a reasonable upper bound on the number of the edges
-	///to add to the front of the path,
-	///using this function you may speed up the building.
-	void reserveFront(size_t) {}
-	///Reserve (back) storage for the builder in advance.
-
-	///If you know a reasonable upper bound on the number of the edges
-	///to add to the back of the path,
-	///using this function you may speed up the building.
-	void reserveBack(size_t) {}
-      };
-
-      template <typename _Path>
-      struct Constraints {
-	void constraints() {
-          typedef typename _Path::Node Node;
-          typedef typename _Path::NodeIt NodeIt;
-          typedef typename Graph::Node GraphNode;
-
-          typedef typename _Path::Edge Edge;
-          typedef typename _Path::EdgeIt EdgeIt;
-          typedef typename Graph::Edge GraphEdge;
-
-          typedef typename _Path::Builder Builder;
-
-          path = _Path(graph);
-
-          bool b = cpath.empty();
-          int l = cpath.length();
-
-          Node gn;
-          Edge ge;
-          gn = cpath.source();
-          gn = cpath.target();
-
-          NodeIt nit;
-          EdgeIt eit(INVALID);
-          nit = path.source(eit);
-          nit = path.target(eit);
-          
-          nit = NodeIt();
-          nit = NodeIt(cpath);
-          nit = INVALID;
-          gn = nit;
-          ++nit;
-          b = nit == nit;
-          b = nit != nit;
-          b = nit < nit;
-
-          eit = EdgeIt();
-          eit = EdgeIt(cpath);
-          eit = INVALID;
-          ge = eit;
-          ++eit;
-          b = eit == eit;
-          b = eit != eit;
-          b = eit < eit;
-
-          size_t st = 0;
-
-          Builder builder(path); 
-          builder.setStartNode(gn);
-          builder.pushFront(ge);
-          builder.pushBack(ge);
-          builder.commit();
-          builder.reserveFront(st);
-          builder.reserveBack(st);
-          
-          ignore_unused_variable_warning(l);
-          ignore_unused_variable_warning(b);
-	}
-
-        const Graph& graph;
-        const _Path& cpath;
-        _Path& path;
-      };
-
-    };
-
-  ///@}
-  }
-
-} // namespace lemon
-
-#endif // LEMON_CONCEPT_PATH_H
Index: lemon/concept/ugraph.h
===================================================================
--- lemon/concept/ugraph.h	(revision 2231)
+++ 	(revision )
@@ -1,713 +1,0 @@
-/* -*- C++ -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library
- *
- * Copyright (C) 2003-2006
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-///\ingroup graph_concepts
-///\file
-///\brief The concept of the undirected graphs.
-
-
-#ifndef LEMON_CONCEPT_UGRAPH_H
-#define LEMON_CONCEPT_UGRAPH_H
-
-#include <lemon/concept/graph_components.h>
-#include <lemon/concept/graph.h>
-#include <lemon/bits/utility.h>
-
-namespace lemon {
-  namespace concept {
-
-    /// \addtogroup graph_concepts
-    /// @{
-
-
-    /// \brief Class describing the concept of Undirected Graphs.
-    ///
-    /// This class describes the common interface of all Undirected
-    /// Graphs.
-    ///
-    /// As all concept describing classes it provides only interface
-    /// without any sensible implementation. So any algorithm for
-    /// undirected graph should compile with this class, but it will not
-    /// run properly, of course.
-    ///
-    /// The LEMON undirected graphs also fulfill the concept of
-    /// directed graphs (\ref lemon::concept::Graph "Graph
-    /// Concept"). Each undirected edges can be seen as two opposite
-    /// directed edge and consequently the undirected graph can be
-    /// seen as the direceted graph of these directed edges. The
-    /// UGraph has the UEdge inner class for the undirected edges and
-    /// the Edge type for the directed edges. The Edge type is
-    /// convertible to UEdge or inherited from it so from a directed
-    /// edge we can get the represented undirected edge.
-    ///
-    /// In the sense of the LEMON each undirected edge has a default
-    /// direction (it should be in every computer implementation,
-    /// because the order of undirected edge's nodes defines an
-    /// orientation). With the default orientation we can define that
-    /// the directed edge is forward or backward directed. With the \c
-    /// direction() and \c direct() function we can get the direction
-    /// of the directed edge and we can direct an undirected edge.
-    ///
-    /// The UEdgeIt is an iterator for the undirected edges. We can use
-    /// the UEdgeMap to map values for the undirected edges. The InEdgeIt and
-    /// OutEdgeIt iterates on the same undirected edges but with opposite
-    /// direction. The IncEdgeIt iterates also on the same undirected edges
-    /// as the OutEdgeIt and InEdgeIt but it is not convertible to Edge just
-    /// to UEdge.  
-    class UGraph {
-    public:
-      /// \brief The undirected graph should be tagged by the
-      /// UndirectedTag.
-      ///
-      /// The undirected graph should be tagged by the UndirectedTag. This
-      /// tag helps the enable_if technics to make compile time 
-      /// specializations for undirected graphs.  
-      typedef True UndirectedTag;
-
-      /// \brief The base type of node iterators, 
-      /// or in other words, the trivial node iterator.
-      ///
-      /// This is the base type of each node iterator,
-      /// thus each kind of node iterator converts to this.
-      /// More precisely each kind of node iterator should be inherited 
-      /// from the trivial node iterator.
-      class Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        Node() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        Node(const Node&) { }
-
-        /// Invalid constructor \& conversion.
-
-        /// This constructor initializes the iterator to be invalid.
-        /// \sa Invalid for more details.
-        Node(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(Node) const { return true; }
-
-        /// Inequality operator
-        
-        /// \sa operator==(Node n)
-        ///
-        bool operator!=(Node) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(Node) const { return false; }
-
-      };
-    
-      /// This iterator goes through each node.
-
-      /// This iterator goes through each node.
-      /// Its usage is quite simple, for example you can count the number
-      /// of nodes in graph \c g of type \c Graph like this:
-      ///\code
-      /// int count=0;
-      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
-      ///\endcode
-      class NodeIt : public Node {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        NodeIt() { }
-        /// Copy constructor.
-        
-        /// Copy constructor.
-        ///
-        NodeIt(const NodeIt& n) : Node(n) { }
-        /// Invalid constructor \& conversion.
-
-        /// Initialize the iterator to be invalid.
-        /// \sa Invalid for more details.
-        NodeIt(Invalid) { }
-        /// Sets the iterator to the first node.
-
-        /// Sets the iterator to the first node of \c g.
-        ///
-        NodeIt(const UGraph&) { }
-        /// Node -> NodeIt conversion.
-
-        /// Sets the iterator to the node of \c the graph pointed by 
-	/// the trivial iterator.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        NodeIt(const UGraph&, const Node&) { }
-        /// Next node.
-
-        /// Assign the iterator to the next node.
-        ///
-        NodeIt& operator++() { return *this; }
-      };
-    
-    
-      /// The base type of the undirected edge iterators.
-
-      /// The base type of the undirected edge iterators.
-      ///
-      class UEdge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        UEdge() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        UEdge(const UEdge&) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        UEdge(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(UEdge) const { return true; }
-        /// Inequality operator
-
-        /// \sa operator==(UEdge n)
-        ///
-        bool operator!=(UEdge) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(UEdge) const { return false; }
-      };
-
-      /// This iterator goes through each undirected edge.
-
-      /// This iterator goes through each undirected edge of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of undirected edges in a graph \c g of type \c Graph as follows:
-      ///\code
-      /// int count=0;
-      /// for(Graph::UEdgeIt e(g); e!=INVALID; ++e) ++count;
-      ///\endcode
-      class UEdgeIt : public UEdge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        UEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        UEdgeIt(const UEdgeIt& e) : UEdge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        UEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first undirected edge.
-    
-        /// This constructor sets the iterator to the first undirected edge.
-        UEdgeIt(const UGraph&) { }
-        /// UEdge -> UEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator.
-        /// This feature necessitates that each time we
-        /// iterate the undirected edge-set, the iteration order is the 
-	/// same.
-        UEdgeIt(const UGraph&, const UEdge&) { } 
-        /// Next undirected edge
-        
-        /// Assign the iterator to the next undirected edge.
-        UEdgeIt& operator++() { return *this; }
-      };
-
-      /// \brief This iterator goes trough the incident undirected 
-      /// edges of a node.
-      ///
-      /// This iterator goes trough the incident undirected edges
-      /// of a certain node of a graph. You should assume that the 
-      /// loop edges will be iterated twice.
-      /// 
-      /// Its usage is quite simple, for example you can compute the
-      /// degree (i.e. count the number of incident edges of a node \c n
-      /// in graph \c g of type \c Graph as follows. 
-      ///
-      ///\code
-      /// int count=0;
-      /// for(Graph::IncEdgeIt e(g, n); e!=INVALID; ++e) ++count;
-      ///\endcode
-      class IncEdgeIt : public UEdge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        IncEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        IncEdgeIt(const IncEdgeIt& e) : UEdge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        IncEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to first incident edge.
-    
-        /// This constructor set the iterator to the first incident edge of
-        /// the node.
-        IncEdgeIt(const UGraph&, const Node&) { }
-        /// UEdge -> IncEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        IncEdgeIt(const UGraph&, const UEdge&) { }
-        /// Next incident edge
-
-        /// Assign the iterator to the next incident edge
-	/// of the corresponding node.
-        IncEdgeIt& operator++() { return *this; }
-      };
-
-      /// The directed edge type.
-
-      /// The directed edge type. It can be converted to the
-      /// undirected edge or it should be inherited from the undirected
-      /// edge.
-      class Edge : public UEdge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        Edge() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        Edge(const Edge& e) : UEdge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        Edge(Invalid) { }
-        /// Equality operator
-
-        /// Two iterators are equal if and only if they point to the
-        /// same object or both are invalid.
-        bool operator==(Edge) const { return true; }
-        /// Inequality operator
-
-        /// \sa operator==(Edge n)
-        ///
-        bool operator!=(Edge) const { return true; }
-
-	/// Artificial ordering operator.
-	
-	/// To allow the use of graph descriptors as key type in std::map or
-	/// similar associative container we require this.
-	///
-	/// \note This operator only have to define some strict ordering of
-	/// the items; this order has nothing to do with the iteration
-	/// ordering of the items.
-	bool operator<(Edge) const { return false; }
-	
-      }; 
-      /// This iterator goes through each directed edge.
-
-      /// This iterator goes through each edge of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of edges in a graph \c g of type \c Graph as follows:
-      ///\code
-      /// int count=0;
-      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
-      ///\endcode
-      class EdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        EdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        EdgeIt(const EdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        EdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first edge.
-    
-        /// This constructor sets the iterator to the first edge of \c g.
-        ///@param g the graph
-        EdgeIt(const UGraph &g) { ignore_unused_variable_warning(g); }
-        /// Edge -> EdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        EdgeIt(const UGraph&, const Edge&) { } 
-        ///Next edge
-        
-        /// Assign the iterator to the next edge.
-        EdgeIt& operator++() { return *this; }
-      };
-   
-      /// This iterator goes trough the outgoing directed edges of a node.
-
-      /// This iterator goes trough the \e outgoing edges of a certain node
-      /// of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of outgoing edges of a node \c n
-      /// in graph \c g of type \c Graph as follows.
-      ///\code
-      /// int count=0;
-      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
-      ///\endcode
-    
-      class OutEdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        OutEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        OutEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to the first outgoing edge.
-    
-        /// This constructor sets the iterator to the first outgoing edge of
-        /// the node.
-        ///@param n the node
-        ///@param g the graph
-        OutEdgeIt(const UGraph& n, const Node& g) {
-	  ignore_unused_variable_warning(n);
-	  ignore_unused_variable_warning(g);
-	}
-        /// Edge -> OutEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator.
-	/// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        OutEdgeIt(const UGraph&, const Edge&) { }
-        ///Next outgoing edge
-        
-        /// Assign the iterator to the next 
-        /// outgoing edge of the corresponding node.
-        OutEdgeIt& operator++() { return *this; }
-      };
-
-      /// This iterator goes trough the incoming directed edges of a node.
-
-      /// This iterator goes trough the \e incoming edges of a certain node
-      /// of a graph.
-      /// Its usage is quite simple, for example you can count the number
-      /// of outgoing edges of a node \c n
-      /// in graph \c g of type \c Graph as follows.
-      ///\code
-      /// int count=0;
-      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
-      ///\endcode
-
-      class InEdgeIt : public Edge {
-      public:
-        /// Default constructor
-
-        /// @warning The default constructor sets the iterator
-        /// to an undefined value.
-        InEdgeIt() { }
-        /// Copy constructor.
-
-        /// Copy constructor.
-        ///
-        InEdgeIt(const InEdgeIt& e) : Edge(e) { }
-        /// Initialize the iterator to be invalid.
-
-        /// Initialize the iterator to be invalid.
-        ///
-        InEdgeIt(Invalid) { }
-        /// This constructor sets the iterator to first incoming edge.
-    
-        /// This constructor set the iterator to the first incoming edge of
-        /// the node.
-        ///@param n the node
-        ///@param g the graph
-        InEdgeIt(const UGraph& g, const Node& n) { 
-	  ignore_unused_variable_warning(n);
-	  ignore_unused_variable_warning(g);
-	}
-        /// Edge -> InEdgeIt conversion
-
-        /// Sets the iterator to the value of the trivial iterator \c e.
-        /// This feature necessitates that each time we 
-        /// iterate the edge-set, the iteration order is the same.
-        InEdgeIt(const UGraph&, const Edge&) { }
-        /// Next incoming edge
-
-        /// Assign the iterator to the next inedge of the corresponding node.
-        ///
-        InEdgeIt& operator++() { return *this; }
-      };
-
-      /// \brief Read write map of the nodes to type \c T.
-      /// 
-      /// ReadWrite map of the nodes to type \c T.
-      /// \sa Reference
-      /// \warning Making maps that can handle bool type (NodeMap<bool>)
-      /// needs some extra attention!
-      template<class T> 
-      class NodeMap : public ReadWriteMap< Node, T >
-      {
-      public:
-
-        ///\e
-        NodeMap(const UGraph&) { }
-        ///\e
-        NodeMap(const UGraph&, T) { }
-
-        ///Copy constructor
-        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
-        ///Assignment operator
-        template <typename CMap>
-        NodeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Node, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// \brief Read write map of the directed edges to type \c T.
-      ///
-      /// Reference map of the directed edges to type \c T.
-      /// \sa Reference
-      /// \warning Making maps that can handle bool type (EdgeMap<bool>)
-      /// needs some extra attention!
-      template<class T> 
-      class EdgeMap : public ReadWriteMap<Edge,T>
-      {
-      public:
-
-        ///\e
-        EdgeMap(const UGraph&) { }
-        ///\e
-        EdgeMap(const UGraph&, T) { }
-        ///Copy constructor
-        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }
-        ///Assignment operator
-        template <typename CMap>
-        EdgeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<Edge, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// Read write map of the undirected edges to type \c T.
-
-      /// Reference map of the edges to type \c T.
-      /// \sa Reference
-      /// \warning Making maps that can handle bool type (UEdgeMap<bool>)
-      /// needs some extra attention!
-      template<class T> 
-      class UEdgeMap : public ReadWriteMap<UEdge,T>
-      {
-      public:
-
-        ///\e
-        UEdgeMap(const UGraph&) { }
-        ///\e
-        UEdgeMap(const UGraph&, T) { }
-        ///Copy constructor
-        UEdgeMap(const UEdgeMap& em) : ReadWriteMap<UEdge,T>(em) {}
-        ///Assignment operator
-        template <typename CMap>
-        UEdgeMap& operator=(const CMap&) { 
-          checkConcept<ReadMap<UEdge, T>, CMap>();
-          return *this; 
-        }
-      };
-
-      /// \brief Direct the given undirected edge.
-      ///
-      /// Direct the given undirected edge. The returned edge source
-      /// will be the given node.
-      Edge direct(const UEdge&, const Node&) const {
-	return INVALID;
-      }
-
-      /// \brief Direct the given undirected edge.
-      ///
-      /// Direct the given undirected edge. The returned edge
-      /// represents the given undireted edge and the direction comes
-      /// from the given bool.  The source of the undirected edge and
-      /// the directed edge is the same when the given bool is true.
-      Edge direct(const UEdge&, bool) const {
-	return INVALID;
-      }
-
-      /// \brief Returns true if the edge has default orientation.
-      ///
-      /// Returns whether the given directed edge is same orientation as
-      /// the corresponding undirected edge's default orientation.
-      bool direction(Edge) const { return true; }
-
-      /// \brief Returns the opposite directed edge.
-      ///
-      /// Returns the opposite directed edge.
-      Edge oppositeEdge(Edge) const { return INVALID; }
-
-      /// \brief Opposite node on an edge
-      ///
-      /// \return the opposite of the given Node on the given UEdge
-      Node oppositeNode(Node, UEdge) const { return INVALID; }
-
-      /// \brief First node of the undirected edge.
-      ///
-      /// \return the first node of the given UEdge.
-      ///
-      /// Naturally undirected edges don't have direction and thus
-      /// don't have source and target node. But we use these two methods
-      /// to query the two nodes of the edge. The direction of the edge
-      /// which arises this way is called the inherent direction of the
-      /// undirected edge, and is used to define the "default" direction
-      /// of the directed versions of the edges.
-      /// \sa direction
-      Node source(UEdge) const { return INVALID; }
-
-      /// \brief Second node of the undirected edge.
-      Node target(UEdge) const { return INVALID; }
-
-      /// \brief Source node of the directed edge.
-      Node source(Edge) const { return INVALID; }
-
-      /// \brief Target node of the directed edge.
-      Node target(Edge) const { return INVALID; }
-
-      void first(Node&) const {}
-      void next(Node&) const {}
-
-      void first(UEdge&) const {}
-      void next(UEdge&) const {}
-
-      void first(Edge&) const {}
-      void next(Edge&) const {}
-
-      void firstOut(Edge&, Node) const {}
-      void nextOut(Edge&) const {}
-
-      void firstIn(Edge&, Node) const {}
-      void nextIn(Edge&) const {}
-
-
-      void firstInc(UEdge &, bool &, const Node &) const {}
-      void nextInc(UEdge &, bool &) const {}
-
-      /// \brief Base node of the iterator
-      ///
-      /// Returns the base node (the source in this case) of the iterator
-      Node baseNode(OutEdgeIt e) const {
-	return source(e);
-      }
-      /// \brief Running node of the iterator
-      ///
-      /// Returns the running node (the target in this case) of the
-      /// iterator
-      Node runningNode(OutEdgeIt e) const {
-	return target(e);
-      }
-
-      /// \brief Base node of the iterator
-      ///
-      /// Returns the base node (the target in this case) of the iterator
-      Node baseNode(InEdgeIt e) const {
-	return target(e);
-      }
-      /// \brief Running node of the iterator
-      ///
-      /// Returns the running node (the source in this case) of the
-      /// iterator
-      Node runningNode(InEdgeIt e) const {
-	return source(e);
-      }
-
-      /// \brief Base node of the iterator
-      ///
-      /// Returns the base node of the iterator
-      Node baseNode(IncEdgeIt) const {
-	return INVALID;
-      }
-      
-      /// \brief Running node of the iterator
-      ///
-      /// Returns the running node of the iterator
-      Node runningNode(IncEdgeIt) const {
-	return INVALID;
-      }
-
-      template <typename Graph>
-      struct Constraints {
-	void constraints() {
-	  checkConcept<IterableUGraphComponent<>, Graph>();
-	  checkConcept<MappableUGraphComponent<>, Graph>();
-	}
-      };
-
-    };
-
-    /// @}
-
-  }
-
-}
-
-#endif
Index: lemon/concepts/bpugraph.h
===================================================================
--- lemon/concepts/bpugraph.h	(revision 2260)
+++ lemon/concepts/bpugraph.h	(revision 2260)
@@ -0,0 +1,1020 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2006
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+/// \ingroup graph_concepts
+/// \file
+/// \brief Undirected bipartite graphs and components of.
+
+
+#ifndef LEMON_CONCEPT_BPUGRAPH_H
+#define LEMON_CONCEPT_BPUGRAPH_H
+
+#include <lemon/concepts/graph_components.h>
+
+#include <lemon/concepts/graph.h>
+#include <lemon/concepts/ugraph.h>
+
+#include <lemon/bits/utility.h>
+
+namespace lemon {
+  namespace concepts {
+
+    /// \addtogroup graph_concepts
+    /// @{
+
+
+    /// \brief Class describing the concept of Bipartite Undirected Graphs.
+    ///
+    /// This class describes the common interface of all 
+    /// Undirected Bipartite Graphs.
+    ///
+    /// As all concept describing classes it provides only interface
+    /// without any sensible implementation. So any algorithm for
+    /// bipartite undirected graph should compile with this class, but it 
+    /// will not run properly, of course.
+    ///
+    /// In LEMON bipartite undirected graphs also fulfill the concept of 
+    /// the undirected graphs (\ref lemon::concepts::UGraph "UGraph Concept"). 
+    ///
+    /// You can assume that all undirected bipartite graph can be handled
+    /// as an undirected graph and consequently as a static graph.
+    ///
+    /// The bipartite graph stores two types of nodes which are named
+    /// ANode and BNode. The graph type contains two types ANode and
+    /// BNode which are inherited from Node type. Moreover they have
+    /// constructor which converts Node to either ANode or BNode when
+    /// it is possible. Therefor everywhere the Node type can be used
+    /// instead of ANode and BNode. So the usage of the ANode and
+    /// BNode is not suggested.
+    ///
+    /// The iteration on the partition can be done with the ANodeIt and 
+    /// BNodeIt classes. The node map can be used to map values to the nodes
+    /// and similarly we can use to map values for just the ANodes and
+    /// BNodes the ANodeMap and BNodeMap template classes.
+
+    class BpUGraph {
+    public:
+      /// \brief The undirected graph should be tagged by the
+      /// UndirectedTag.
+      ///
+      /// The undirected graph should be tagged by the UndirectedTag. This
+      /// tag helps the enable_if technics to make compile time 
+      /// specializations for undirected graphs.  
+      typedef True UndirectedTag;
+
+      /// \brief The base type of node iterators, 
+      /// or in other words, the trivial node iterator.
+      ///
+      /// This is the base type of each node iterator,
+      /// thus each kind of node iterator converts to this.
+      /// More precisely each kind of node iterator should be inherited 
+      /// from the trivial node iterator. The Node class represents
+      /// both of two types of nodes. 
+      class Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        Node() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        Node(const Node&) { }
+
+        /// Invalid constructor \& conversion.
+
+        /// This constructor initializes the iterator to be invalid.
+        /// \sa Invalid for more details.
+        Node(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(Node) const { return true; }
+
+        /// Inequality operator
+        
+        /// \sa operator==(Node n)
+        ///
+        bool operator!=(Node) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(Node) const { return false; }
+
+      };
+
+      /// \brief Helper class for ANodes.
+      ///
+      /// This class is just a helper class for ANodes, it is not
+      /// suggested to use it directly. It can be converted easily to
+      /// node and vice versa. The usage of this class is limited
+      /// to use just as template parameters for special map types. 
+      class ANode : public Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        ANode() : Node() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        ANode(const ANode&) : Node() { }
+
+        /// Construct the same node as ANode.
+
+        /// Construct the same node as ANode. It may throws assertion
+        /// when the given node is from the BNode set.
+        ANode(const Node&) : Node() { }
+
+        /// Assign node to A-node.
+
+        /// Besides the core graph item functionality each node should
+        /// be convertible to the represented A-node if it is it possible. 
+        ANode& operator=(const Node&) { return *this; }
+
+        /// Invalid constructor \& conversion.
+
+        /// This constructor initializes the iterator to be invalid.
+        /// \sa Invalid for more details.
+        ANode(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(ANode) const { return true; }
+
+        /// Inequality operator
+        
+        /// \sa operator==(ANode n)
+        ///
+        bool operator!=(ANode) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(ANode) const { return false; }
+
+      };
+
+      /// \brief Helper class for BNodes.
+      ///
+      /// This class is just a helper class for BNodes, it is not
+      /// suggested to use it directly. It can be converted easily to
+      /// node and vice versa. The usage of this class is limited
+      /// to use just as template parameters for special map types. 
+      class BNode : public Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        BNode() : Node() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        BNode(const BNode&) : Node() { }
+
+        /// Construct the same node as BNode.
+
+        /// Construct the same node as BNode. It may throws assertion
+        /// when the given node is from the ANode set.
+        BNode(const Node&) : Node() { }
+
+        /// Assign node to B-node.
+
+        /// Besides the core graph item functionality each node should
+        /// be convertible to the represented B-node if it is it possible. 
+        BNode& operator=(const Node&) { return *this; }
+
+        /// Invalid constructor \& conversion.
+
+        /// This constructor initializes the iterator to be invalid.
+        /// \sa Invalid for more details.
+        BNode(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(BNode) const { return true; }
+
+        /// Inequality operator
+        
+        /// \sa operator==(BNode n)
+        ///
+        bool operator!=(BNode) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(BNode) const { return false; }
+
+      };
+    
+      /// This iterator goes through each node.
+
+      /// This iterator goes through each node.
+      /// Its usage is quite simple, for example you can count the number
+      /// of nodes in graph \c g of type \c Graph like this:
+      ///\code
+      /// int count=0;
+      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
+      ///\endcode
+      class NodeIt : public Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        NodeIt() { }
+        /// Copy constructor.
+        
+        /// Copy constructor.
+        ///
+        NodeIt(const NodeIt& n) : Node(n) { }
+        /// Invalid constructor \& conversion.
+
+        /// Initialize the iterator to be invalid.
+        /// \sa Invalid for more details.
+        NodeIt(Invalid) { }
+        /// Sets the iterator to the first node.
+
+        /// Sets the iterator to the first node of \c g.
+        ///
+        NodeIt(const BpUGraph&) { }
+        /// Node -> NodeIt conversion.
+
+        /// Sets the iterator to the node of \c the graph pointed by 
+	/// the trivial iterator.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        NodeIt(const BpUGraph&, const Node&) { }
+        /// Next node.
+
+        /// Assign the iterator to the next node.
+        ///
+        NodeIt& operator++() { return *this; }
+      };
+
+      /// This iterator goes through each ANode.
+
+      /// This iterator goes through each ANode.
+      /// Its usage is quite simple, for example you can count the number
+      /// of nodes in graph \c g of type \c Graph like this:
+      ///\code
+      /// int count=0;
+      /// for (Graph::ANodeIt n(g); n!=INVALID; ++n) ++count;
+      ///\endcode
+      class ANodeIt : public Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        ANodeIt() { }
+        /// Copy constructor.
+        
+        /// Copy constructor.
+        ///
+        ANodeIt(const ANodeIt& n) : Node(n) { }
+        /// Invalid constructor \& conversion.
+
+        /// Initialize the iterator to be invalid.
+        /// \sa Invalid for more details.
+        ANodeIt(Invalid) { }
+        /// Sets the iterator to the first node.
+
+        /// Sets the iterator to the first node of \c g.
+        ///
+        ANodeIt(const BpUGraph&) { }
+        /// Node -> ANodeIt conversion.
+
+        /// Sets the iterator to the node of \c the graph pointed by 
+	/// the trivial iterator.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        ANodeIt(const BpUGraph&, const Node&) { }
+        /// Next node.
+
+        /// Assign the iterator to the next node.
+        ///
+        ANodeIt& operator++() { return *this; }
+      };
+
+      /// This iterator goes through each BNode.
+
+      /// This iterator goes through each BNode.
+      /// Its usage is quite simple, for example you can count the number
+      /// of nodes in graph \c g of type \c Graph like this:
+      ///\code
+      /// int count=0;
+      /// for (Graph::BNodeIt n(g); n!=INVALID; ++n) ++count;
+      ///\endcode
+      class BNodeIt : public Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        BNodeIt() { }
+        /// Copy constructor.
+        
+        /// Copy constructor.
+        ///
+        BNodeIt(const BNodeIt& n) : Node(n) { }
+        /// Invalid constructor \& conversion.
+
+        /// Initialize the iterator to be invalid.
+        /// \sa Invalid for more details.
+        BNodeIt(Invalid) { }
+        /// Sets the iterator to the first node.
+
+        /// Sets the iterator to the first node of \c g.
+        ///
+        BNodeIt(const BpUGraph&) { }
+        /// Node -> BNodeIt conversion.
+
+        /// Sets the iterator to the node of \c the graph pointed by 
+	/// the trivial iterator.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        BNodeIt(const BpUGraph&, const Node&) { }
+        /// Next node.
+
+        /// Assign the iterator to the next node.
+        ///
+        BNodeIt& operator++() { return *this; }
+      };
+    
+    
+      /// The base type of the undirected edge iterators.
+
+      /// The base type of the undirected edge iterators.
+      ///
+      class UEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        UEdge() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        UEdge(const UEdge&) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        UEdge(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(UEdge) const { return true; }
+        /// Inequality operator
+
+        /// \sa operator==(UEdge n)
+        ///
+        bool operator!=(UEdge) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(UEdge) const { return false; }
+      };
+
+      /// This iterator goes through each undirected edge.
+
+      /// This iterator goes through each undirected edge of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of undirected edges in a graph \c g of type \c Graph as follows:
+      ///\code
+      /// int count=0;
+      /// for(Graph::UEdgeIt e(g); e!=INVALID; ++e) ++count;
+      ///\endcode
+      class UEdgeIt : public UEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        UEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        UEdgeIt(const UEdgeIt& e) : UEdge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        UEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first undirected edge.
+    
+        /// This constructor sets the iterator to the first undirected edge.
+        UEdgeIt(const BpUGraph&) { }
+        /// UEdge -> UEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator.
+        /// This feature necessitates that each time we
+        /// iterate the undirected edge-set, the iteration order is the 
+	/// same.
+        UEdgeIt(const BpUGraph&, const UEdge&) { } 
+        /// Next undirected edge
+        
+        /// Assign the iterator to the next undirected edge.
+        UEdgeIt& operator++() { return *this; }
+      };
+
+      /// \brief This iterator goes trough the incident undirected 
+      /// edges of a node.
+      ///
+      /// This iterator goes trough the incident undirected edges
+      /// of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can compute the
+      /// degree (i.e. count the number
+      /// of incident edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      ///\code
+      /// int count=0;
+      /// for(Graph::IncEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      ///\endcode
+      class IncEdgeIt : public UEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        IncEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        IncEdgeIt(const IncEdgeIt& e) : UEdge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        IncEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to first incident edge.
+    
+        /// This constructor set the iterator to the first incident edge of
+        /// the node.
+        IncEdgeIt(const BpUGraph&, const Node&) { }
+        /// UEdge -> IncEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        IncEdgeIt(const BpUGraph&, const UEdge&) { }
+        /// Next incident edge
+
+        /// Assign the iterator to the next incident edge
+	/// of the corresponding node.
+        IncEdgeIt& operator++() { return *this; }
+      };
+
+      /// The directed edge type.
+
+      /// The directed edge type. It can be converted to the
+      /// undirected edge.
+      class Edge : public UEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        Edge() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        Edge(const Edge& e) : UEdge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        Edge(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(Edge) const { return true; }
+        /// Inequality operator
+
+        /// \sa operator==(Edge n)
+        ///
+        bool operator!=(Edge) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(Edge) const { return false; }
+	
+      }; 
+      /// This iterator goes through each directed edge.
+
+      /// This iterator goes through each edge of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of edges in a graph \c g of type \c Graph as follows:
+      ///\code
+      /// int count=0;
+      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
+      ///\endcode
+      class EdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        EdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        EdgeIt(const EdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        EdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first edge.
+    
+        /// This constructor sets the iterator to the first edge of \c g.
+        ///@param g the graph
+        EdgeIt(const BpUGraph &g) { ignore_unused_variable_warning(g); }
+        /// Edge -> EdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        EdgeIt(const BpUGraph&, const Edge&) { } 
+        ///Next edge
+        
+        /// Assign the iterator to the next edge.
+        EdgeIt& operator++() { return *this; }
+      };
+   
+      /// This iterator goes trough the outgoing directed edges of a node.
+
+      /// This iterator goes trough the \e outgoing edges of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of outgoing edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      ///\code
+      /// int count=0;
+      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      ///\endcode
+    
+      class OutEdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        OutEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        OutEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first outgoing edge.
+    
+        /// This constructor sets the iterator to the first outgoing edge of
+        /// the node.
+        ///@param n the node
+        ///@param g the graph
+        OutEdgeIt(const BpUGraph& n, const Node& g) {
+	  ignore_unused_variable_warning(n);
+	  ignore_unused_variable_warning(g);
+	}
+        /// Edge -> OutEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator.
+	/// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        OutEdgeIt(const BpUGraph&, const Edge&) { }
+        ///Next outgoing edge
+        
+        /// Assign the iterator to the next 
+        /// outgoing edge of the corresponding node.
+        OutEdgeIt& operator++() { return *this; }
+      };
+
+      /// This iterator goes trough the incoming directed edges of a node.
+
+      /// This iterator goes trough the \e incoming edges of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of outgoing edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      ///\code
+      /// int count=0;
+      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      ///\endcode
+
+      class InEdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        InEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        InEdgeIt(const InEdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        InEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to first incoming edge.
+    
+        /// This constructor set the iterator to the first incoming edge of
+        /// the node.
+        ///@param n the node
+        ///@param g the graph
+        InEdgeIt(const BpUGraph& g, const Node& n) { 
+	  ignore_unused_variable_warning(n);
+	  ignore_unused_variable_warning(g);
+	}
+        /// Edge -> InEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        InEdgeIt(const BpUGraph&, const Edge&) { }
+        /// Next incoming edge
+
+        /// Assign the iterator to the next inedge of the corresponding node.
+        ///
+        InEdgeIt& operator++() { return *this; }
+      };
+
+      /// \brief Read write map of the nodes to type \c T.
+      /// 
+      /// ReadWrite map of the nodes to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (NodeMap<bool>)
+      /// needs some extra attention!
+      /// \todo Wrong documentation
+      template<class T> 
+      class NodeMap : public ReadWriteMap< Node, T >
+      {
+      public:
+
+        ///\e
+        NodeMap(const BpUGraph&) { }
+        ///\e
+        NodeMap(const BpUGraph&, T) { }
+
+        ///Copy constructor
+        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
+        ///Assignment operator
+        NodeMap& operator=(const NodeMap&) { return *this; }
+        ///Assignment operator
+        template <typename CMap>
+        NodeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Node, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// \brief Read write map of the ANodes to type \c T.
+      /// 
+      /// ReadWrite map of the ANodes to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (NodeMap<bool>)
+      /// needs some extra attention!
+      /// \todo Wrong documentation
+      template<class T> 
+      class ANodeMap : public ReadWriteMap< Node, T >
+      {
+      public:
+
+        ///\e
+        ANodeMap(const BpUGraph&) { }
+        ///\e
+        ANodeMap(const BpUGraph&, T) { }
+
+        ///Copy constructor
+        ANodeMap(const ANodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
+        ///Assignment operator
+        ANodeMap& operator=(const ANodeMap&) { return *this; }
+        ///Assignment operator
+        template <typename CMap>
+        ANodeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Node, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// \brief Read write map of the BNodes to type \c T.
+      /// 
+      /// ReadWrite map of the BNodes to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (NodeMap<bool>)
+      /// needs some extra attention!
+      /// \todo Wrong documentation
+      template<class T> 
+      class BNodeMap : public ReadWriteMap< Node, T >
+      {
+      public:
+
+        ///\e
+        BNodeMap(const BpUGraph&) { }
+        ///\e
+        BNodeMap(const BpUGraph&, T) { }
+
+        ///Copy constructor
+        BNodeMap(const BNodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
+        ///Assignment operator
+        BNodeMap& operator=(const BNodeMap&) { return *this; }
+        ///Assignment operator
+        template <typename CMap>
+        BNodeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Node, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// \brief Read write map of the directed edges to type \c T.
+      ///
+      /// Reference map of the directed edges to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (EdgeMap<bool>)
+      /// needs some extra attention!
+      /// \todo Wrong documentation
+      template<class T> 
+      class EdgeMap : public ReadWriteMap<Edge,T>
+      {
+      public:
+
+        ///\e
+        EdgeMap(const BpUGraph&) { }
+        ///\e
+        EdgeMap(const BpUGraph&, T) { }
+        ///Copy constructor
+        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }
+        ///Assignment operator
+        EdgeMap& operator=(const EdgeMap&) { return *this; }
+        ///Assignment operator
+        template <typename CMap>
+        EdgeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Edge, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// Read write map of the undirected edges to type \c T.
+
+      /// Reference map of the edges to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (UEdgeMap<bool>)
+      /// needs some extra attention!
+      /// \todo Wrong documentation
+      template<class T> 
+      class UEdgeMap : public ReadWriteMap<UEdge,T>
+      {
+      public:
+
+        ///\e
+        UEdgeMap(const BpUGraph&) { }
+        ///\e
+        UEdgeMap(const BpUGraph&, T) { }
+        ///Copy constructor
+        UEdgeMap(const UEdgeMap& em) : ReadWriteMap<UEdge,T>(em) {}
+        ///Assignment operator
+        UEdgeMap &operator=(const UEdgeMap&) { return *this; }
+        ///Assignment operator
+        template <typename CMap>
+        UEdgeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<UEdge, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// \brief Direct the given undirected edge.
+      ///
+      /// Direct the given undirected edge. The returned edge source
+      /// will be the given node.
+      Edge direct(const UEdge&, const Node&) const {
+	return INVALID;
+      }
+
+      /// \brief Direct the given undirected edge.
+      ///
+      /// Direct the given undirected edge. The returned edge
+      /// represents the given undireted edge and the direction comes
+      /// from the given bool.  The source of the undirected edge and
+      /// the directed edge is the same when the given bool is true.
+      Edge direct(const UEdge&, bool) const {
+	return INVALID;
+      }
+
+      /// \brief Returns true when the given node is an ANode.
+      ///
+      /// Returns true when the given node is an ANode.
+      bool aNode(Node) const { return true;}
+
+      /// \brief Returns true when the given node is an BNode.
+      ///
+      /// Returns true when the given node is an BNode.
+      bool bNode(Node) const { return true;}
+
+      /// \brief Returns the edge's end node which is in the ANode set.
+      ///
+      /// Returns the edge's end node which is in the ANode set.
+      Node aNode(UEdge) const { return INVALID;}
+
+      /// \brief Returns the edge's end node which is in the BNode set.
+      ///
+      /// Returns the edge's end node which is in the BNode set.
+      Node bNode(UEdge) const { return INVALID;}
+
+      /// \brief Returns true if the edge has default orientation.
+      ///
+      /// Returns whether the given directed edge is same orientation as
+      /// the corresponding undirected edge's default orientation.
+      bool direction(Edge) const { return true; }
+
+      /// \brief Returns the opposite directed edge.
+      ///
+      /// Returns the opposite directed edge.
+      Edge oppositeEdge(Edge) const { return INVALID; }
+
+      /// \brief Opposite node on an edge
+      ///
+      /// \return the opposite of the given Node on the given UEdge
+      Node oppositeNode(Node, UEdge) const { return INVALID; }
+
+      /// \brief First node of the undirected edge.
+      ///
+      /// \return the first node of the given UEdge.
+      ///
+      /// Naturally undirected edges don't have direction and thus
+      /// don't have source and target node. But we use these two methods
+      /// to query the two endnodes of the edge. The direction of the edge
+      /// which arises this way is called the inherent direction of the
+      /// undirected edge, and is used to define the "default" direction
+      /// of the directed versions of the edges.
+      /// \sa direction
+      Node source(UEdge) const { return INVALID; }
+
+      /// \brief Second node of the undirected edge.
+      Node target(UEdge) const { return INVALID; }
+
+      /// \brief Source node of the directed edge.
+      Node source(Edge) const { return INVALID; }
+
+      /// \brief Target node of the directed edge.
+      Node target(Edge) const { return INVALID; }
+
+      /// \brief Base node of the iterator
+      ///
+      /// Returns the base node (the source in this case) of the iterator
+      Node baseNode(OutEdgeIt e) const {
+	return source(e);
+      }
+
+      /// \brief Running node of the iterator
+      ///
+      /// Returns the running node (the target in this case) of the
+      /// iterator
+      Node runningNode(OutEdgeIt e) const {
+	return target(e);
+      }
+
+      /// \brief Base node of the iterator
+      ///
+      /// Returns the base node (the target in this case) of the iterator
+      Node baseNode(InEdgeIt e) const {
+	return target(e);
+      }
+      /// \brief Running node of the iterator
+      ///
+      /// Returns the running node (the source in this case) of the
+      /// iterator
+      Node runningNode(InEdgeIt e) const {
+	return source(e);
+      }
+
+      /// \brief Base node of the iterator
+      ///
+      /// Returns the base node of the iterator
+      Node baseNode(IncEdgeIt) const {
+	return INVALID;
+      }
+      
+      /// \brief Running node of the iterator
+      ///
+      /// Returns the running node of the iterator
+      Node runningNode(IncEdgeIt) const {
+	return INVALID;
+      }
+
+      void first(Node&) const {}
+      void next(Node&) const {}
+
+      void first(Edge&) const {}
+      void next(Edge&) const {}
+
+      void first(UEdge&) const {}
+      void next(UEdge&) const {}
+
+      void firstANode(Node&) const {}
+      void nextANode(Node&) const {}
+
+      void firstBNode(Node&) const {}
+      void nextBNode(Node&) const {}
+
+      void firstIn(Edge&, const Node&) const {}
+      void nextIn(Edge&) const {}
+
+      void firstOut(Edge&, const Node&) const {}
+      void nextOut(Edge&) const {}
+
+      void firstInc(UEdge &, bool &, const Node &) const {}
+      void nextInc(UEdge &, bool &) const {}
+
+      void firstFromANode(UEdge&, const Node&) const {}
+      void nextFromANode(UEdge&) const {}
+
+      void firstFromBNode(UEdge&, const Node&) const {}
+      void nextFromBNode(UEdge&) const {}
+
+      template <typename Graph>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<IterableBpUGraphComponent<>, Graph>();
+	  checkConcept<MappableBpUGraphComponent<>, Graph>();
+	}
+      };
+
+    };
+
+
+    /// @}
+
+  }
+
+}
+
+#endif
Index: lemon/concepts/graph.h
===================================================================
--- lemon/concepts/graph.h	(revision 2260)
+++ lemon/concepts/graph.h	(revision 2260)
@@ -0,0 +1,455 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2006
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#ifndef LEMON_CONCEPT_GRAPH_H
+#define LEMON_CONCEPT_GRAPH_H
+
+///\ingroup graph_concepts
+///\file
+///\brief Declaration of Graph.
+
+#include <lemon/bits/invalid.h>
+#include <lemon/bits/utility.h>
+#include <lemon/concepts/maps.h>
+#include <lemon/concept_check.h>
+#include <lemon/concepts/graph_components.h>
+
+namespace lemon {
+  namespace concepts {
+
+    /// \addtogroup graph_concepts
+    /// @{
+
+    /// The directed graph concept
+
+    /// This class describes the \ref concept "concept" of the
+    /// immutable directed graphs.
+    ///
+    /// Note that actual graph implementation like @ref ListGraph or
+    /// @ref SmartGraph may have several additional functionality.
+    ///
+    /// \sa concept
+    class Graph {
+    private:
+      ///Graphs are \e not copy constructible. Use GraphCopy() instead.
+      
+      ///Graphs are \e not copy constructible. Use GraphCopy() instead.
+      ///
+      Graph(const Graph &) {};
+      ///\brief Assignment of \ref Graph "Graph"s to another ones are
+      ///\e not allowed. Use GraphCopy() instead.
+      
+      ///Assignment of \ref Graph "Graph"s to another ones are
+      ///\e not allowed.  Use GraphCopy() instead.
+
+      void operator=(const Graph &) {}
+    public:
+      ///\e
+
+      /// Defalult constructor.
+
+      /// Defalult constructor.
+      ///
+      Graph() { }
+      /// Class for identifying a node of the graph
+
+      /// This class identifies a node of the graph. It also serves
+      /// as a base class of the node iterators,
+      /// thus they will convert to this type.
+      class Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        Node() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        Node(const Node&) { }
+
+        /// Invalid constructor \& conversion.
+
+        /// This constructor initializes the iterator to be invalid.
+        /// \sa Invalid for more details.
+        Node(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(Node) const { return true; }
+
+        /// Inequality operator
+        
+        /// \sa operator==(Node n)
+        ///
+        bool operator!=(Node) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(Node) const { return false; }
+
+      };
+    
+      /// This iterator goes through each node.
+
+      /// This iterator goes through each node.
+      /// Its usage is quite simple, for example you can count the number
+      /// of nodes in graph \c g of type \c Graph like this:
+      ///\code
+      /// int count=0;
+      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
+      ///\endcode
+      class NodeIt : public Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        NodeIt() { }
+        /// Copy constructor.
+        
+        /// Copy constructor.
+        ///
+        NodeIt(const NodeIt& n) : Node(n) { }
+        /// Invalid constructor \& conversion.
+
+        /// Initialize the iterator to be invalid.
+        /// \sa Invalid for more details.
+        NodeIt(Invalid) { }
+        /// Sets the iterator to the first node.
+
+        /// Sets the iterator to the first node of \c g.
+        ///
+        NodeIt(const Graph&) { }
+        /// Node -> NodeIt conversion.
+
+        /// Sets the iterator to the node of \c the graph pointed by 
+	/// the trivial iterator.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        NodeIt(const Graph&, const Node&) { }
+        /// Next node.
+
+        /// Assign the iterator to the next node.
+        ///
+        NodeIt& operator++() { return *this; }
+      };
+    
+    
+      /// Class for identifying an edge of the graph
+
+      /// This class identifies an edge of the graph. It also serves
+      /// as a base class of the edge iterators,
+      /// thus they will convert to this type.
+      class Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        Edge() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        Edge(const Edge&) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        Edge(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(Edge) const { return true; }
+        /// Inequality operator
+
+        /// \sa operator==(Edge n)
+        ///
+        bool operator!=(Edge) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(Edge) const { return false; }
+      };
+    
+      /// This iterator goes trough the outgoing edges of a node.
+
+      /// This iterator goes trough the \e outgoing edges of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of outgoing edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      ///\code
+      /// int count=0;
+      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      ///\endcode
+    
+      class OutEdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        OutEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        OutEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first outgoing edge.
+    
+        /// This constructor sets the iterator to the first outgoing edge of
+        /// the node.
+        OutEdgeIt(const Graph&, const Node&) { }
+        /// Edge -> OutEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator.
+	/// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        OutEdgeIt(const Graph&, const Edge&) { }
+        ///Next outgoing edge
+        
+        /// Assign the iterator to the next 
+        /// outgoing edge of the corresponding node.
+        OutEdgeIt& operator++() { return *this; }
+      };
+
+      /// This iterator goes trough the incoming edges of a node.
+
+      /// This iterator goes trough the \e incoming edges of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of outgoing edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      ///\code
+      /// int count=0;
+      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      ///\endcode
+
+      class InEdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        InEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        InEdgeIt(const InEdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        InEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to first incoming edge.
+    
+        /// This constructor set the iterator to the first incoming edge of
+        /// the node.
+        InEdgeIt(const Graph&, const Node&) { }
+        /// Edge -> InEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        InEdgeIt(const Graph&, const Edge&) { }
+        /// Next incoming edge
+
+        /// Assign the iterator to the next inedge of the corresponding node.
+        ///
+        InEdgeIt& operator++() { return *this; }
+      };
+      /// This iterator goes through each edge.
+
+      /// This iterator goes through each edge of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of edges in a graph \c g of type \c Graph as follows:
+      ///\code
+      /// int count=0;
+      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
+      ///\endcode
+      class EdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        EdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        EdgeIt(const EdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        EdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first edge.
+    
+        /// This constructor sets the iterator to the first edge of \c g.
+        ///@param g the graph
+        EdgeIt(const Graph& g) { ignore_unused_variable_warning(g); }
+        /// Edge -> EdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        EdgeIt(const Graph&, const Edge&) { } 
+        ///Next edge
+        
+        /// Assign the iterator to the next edge.
+        EdgeIt& operator++() { return *this; }
+      };
+      ///Gives back the target node of an edge.
+
+      ///Gives back the target node of an edge.
+      ///
+      Node target(Edge) const { return INVALID; }
+      ///Gives back the source node of an edge.
+
+      ///Gives back the source node of an edge.
+      ///
+      Node source(Edge) const { return INVALID; }
+
+      void first(Node&) const {}
+      void next(Node&) const {}
+
+      void first(Edge&) const {}
+      void next(Edge&) const {}
+
+
+      void firstIn(Edge&, const Node&) const {}
+      void nextIn(Edge&) const {}
+
+      void firstOut(Edge&, const Node&) const {}
+      void nextOut(Edge&) const {}
+
+      /// \brief The base node of the iterator.
+      ///
+      /// Gives back the base node of the iterator.
+      /// It is always the target of the pointed edge.
+      Node baseNode(const InEdgeIt&) const { return INVALID; }
+
+      /// \brief The running node of the iterator.
+      ///
+      /// Gives back the running node of the iterator.
+      /// It is always the source of the pointed edge.
+      Node runningNode(const InEdgeIt&) const { return INVALID; }
+
+      /// \brief The base node of the iterator.
+      ///
+      /// Gives back the base node of the iterator.
+      /// It is always the source of the pointed edge.
+      Node baseNode(const OutEdgeIt&) const { return INVALID; }
+
+      /// \brief The running node of the iterator.
+      ///
+      /// Gives back the running node of the iterator.
+      /// It is always the target of the pointed edge.
+      Node runningNode(const OutEdgeIt&) const { return INVALID; }
+
+      /// \brief The opposite node on the given edge.
+      ///
+      /// Gives back the opposite node on the given edge.
+      Node oppositeNode(const Node&, const Edge&) const { return INVALID; }
+
+      /// \brief Read write map of the nodes to type \c T.
+      /// 
+      /// ReadWrite map of the nodes to type \c T.
+      /// \sa Reference
+      template<class T> 
+      class NodeMap : public ReadWriteMap< Node, T > {
+      public:
+
+        ///\e
+        NodeMap(const Graph&) { }
+        ///\e
+        NodeMap(const Graph&, T) { }
+
+        ///Copy constructor
+        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
+        ///Assignment operator
+        template <typename CMap>
+        NodeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Node, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// \brief Read write map of the edges to type \c T.
+      ///
+      /// Reference map of the edges to type \c T.
+      /// \sa Reference
+      template<class T> 
+      class EdgeMap : public ReadWriteMap<Edge,T> {
+      public:
+
+        ///\e
+        EdgeMap(const Graph&) { }
+        ///\e
+        EdgeMap(const Graph&, T) { }
+        ///Copy constructor
+        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }
+        ///Assignment operator
+        template <typename CMap>
+        EdgeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Edge, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      template <typename RGraph>
+      struct Constraints {
+        void constraints() {
+          checkConcept<IterableGraphComponent<>, Graph>();
+          checkConcept<MappableGraphComponent<>, Graph>();
+        }
+      };
+
+    };
+    
+    // @}
+  } //namespace concepts  
+} //namespace lemon
+
+
+
+#endif // LEMON_CONCEPT_GRAPH_H
Index: lemon/concepts/graph_components.h
===================================================================
--- lemon/concepts/graph_components.h	(revision 2260)
+++ lemon/concepts/graph_components.h	(revision 2260)
@@ -0,0 +1,2103 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2006
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+///\ingroup graph_concepts
+///\file
+///\brief The concept of the graph components.
+
+
+#ifndef LEMON_CONCEPT_GRAPH_COMPONENTS_H
+#define LEMON_CONCEPT_GRAPH_COMPONENTS_H
+
+#include <lemon/bits/invalid.h>
+#include <lemon/concepts/maps.h>
+
+#include <lemon/bits/alteration_notifier.h>
+
+namespace lemon {
+  namespace concepts {
+
+    /// \brief Skeleton class for graph Node and Edge types
+    ///
+    /// This class describes the interface of Node and Edge (and UEdge
+    /// in undirected graphs) subtypes of graph types.
+    ///
+    /// \note This class is a template class so that we can use it to
+    /// create graph skeleton classes. The reason for this is than Node
+    /// and Edge types should \em not derive from the same base class.
+    /// For Node you should instantiate it with character 'n' and for Edge
+    /// with 'e'.
+
+#ifndef DOXYGEN
+    template <char _selector = '0'>
+#endif
+    class GraphItem {
+    public:
+      /// \brief Default constructor.
+      ///      
+      /// \warning The default constructor is not required to set
+      /// the item to some well-defined value. So you should consider it
+      /// as uninitialized.
+      GraphItem() {}
+      /// \brief Copy constructor.
+      ///
+      /// Copy constructor.
+      ///
+      GraphItem(const GraphItem &) {}
+      /// \brief Invalid constructor \& conversion.
+      ///
+      /// This constructor initializes the item to be invalid.
+      /// \sa Invalid for more details.
+      GraphItem(Invalid) {}
+      /// \brief Assign operator for nodes.
+      ///
+      /// The nodes are assignable. 
+      ///
+      GraphItem& operator=(GraphItem const&) { return *this; }
+      /// \brief Equality operator.
+      ///
+      /// Two iterators are equal if and only if they represents the
+      /// same node in the graph or both are invalid.
+      bool operator==(GraphItem) const { return false; }
+      /// \brief Inequality operator.
+      ///
+      /// \sa operator==(const Node& n)
+      ///
+      bool operator!=(GraphItem) const { return false; }
+
+      /// \brief Artificial ordering operator.
+      ///
+      /// To allow the use of graph descriptors as key type in std::map or
+      /// similar associative container we require this.
+      ///
+      /// \note This operator only have to define some strict ordering of
+      /// the items; this order has nothing to do with the iteration
+      /// ordering of the items.
+      bool operator<(GraphItem) const { return false; }
+
+      template<typename _GraphItem>
+      struct Constraints {
+	void constraints() {
+	  _GraphItem i1;
+	  _GraphItem i2 = i1;
+	  _GraphItem i3 = INVALID;
+	  
+	  i1 = i2 = i3;
+
+	  bool b;
+	  //	  b = (ia == ib) && (ia != ib) && (ia < ib);
+	  b = (ia == ib) && (ia != ib);
+	  b = (ia == INVALID) && (ib != INVALID);
+          b = (ia < ib);
+	}
+
+	const _GraphItem &ia;
+	const _GraphItem &ib;
+      };
+    };
+
+    /// \brief An empty base graph class.
+    ///  
+    /// This class provides the minimal set of features needed for a graph
+    /// structure. All graph concepts have to be conform to this base
+    /// graph. It just provides types for nodes and edges and functions to
+    /// get the source and the target of the edges.
+    class BaseGraphComponent {
+    public:
+
+      typedef BaseGraphComponent Graph;
+      
+      /// \brief Node class of the graph.
+      ///
+      /// This class represents the Nodes of the graph. 
+      ///
+      typedef GraphItem<'n'> Node;
+
+      /// \brief Edge class of the graph.
+      ///
+      /// This class represents the Edges of the graph. 
+      ///
+      typedef GraphItem<'e'> Edge;
+
+      /// \brief Gives back the target node of an edge.
+      ///
+      /// Gives back the target node of an edge.
+      ///
+      Node target(const Edge&) const { return INVALID;}
+
+      /// \brief Gives back the source node of an edge.
+      ///
+      /// Gives back the source node of an edge.
+      ///
+      Node source(const Edge&) const { return INVALID;}
+
+      /// \brief Gives back the opposite node on the given edge.
+      ///
+      /// Gives back the opposite node on the given edge.
+      Node oppositeNode(const Node&, const Edge&) const {
+        return INVALID;
+      }
+
+      template <typename _Graph>
+      struct Constraints {
+	typedef typename _Graph::Node Node;
+	typedef typename _Graph::Edge Edge;
+      
+	void constraints() {
+	  checkConcept<GraphItem<'n'>, Node>();
+	  checkConcept<GraphItem<'e'>, Edge>();
+	  {
+	    Node n;
+	    Edge e(INVALID);
+	    n = graph.source(e);
+	    n = graph.target(e);
+            n = graph.oppositeNode(n, e);
+	  }      
+	}
+      
+	const _Graph& graph;
+      };
+    };
+
+    /// \brief An empty base undirected graph class.
+    ///  
+    /// This class provides the minimal set of features needed for an
+    /// undirected graph structure. All undirected graph concepts have
+    /// to be conform to this base graph. It just provides types for
+    /// nodes, edges and undirected edges and functions to get the
+    /// source and the target of the edges and undirected edges,
+    /// conversion from edges to undirected edges and function to get
+    /// both direction of the undirected edges.
+    class BaseUGraphComponent : public BaseGraphComponent {
+    public:
+      typedef BaseGraphComponent::Node Node;
+      typedef BaseGraphComponent::Edge Edge;
+      /// \brief Undirected edge class of the graph.
+      ///
+      /// This class represents the undirected edges of the graph.
+      /// The undirected graphs can be used as a directed graph which
+      /// for each edge contains the opposite edge too so the graph is
+      /// bidirected. The undirected edge represents two opposite
+      /// directed edges.
+      class UEdge : public GraphItem<'u'> {
+      public:
+        typedef GraphItem<'u'> Parent;
+        /// \brief Default constructor.
+        ///      
+        /// \warning The default constructor is not required to set
+        /// the item to some well-defined value. So you should consider it
+        /// as uninitialized.
+        UEdge() {}
+        /// \brief Copy constructor.
+        ///
+        /// Copy constructor.
+        ///
+        UEdge(const UEdge &) : Parent() {}
+        /// \brief Invalid constructor \& conversion.
+        ///
+        /// This constructor initializes the item to be invalid.
+        /// \sa Invalid for more details.
+        UEdge(Invalid) {}
+        /// \brief Converter from edge to undirected edge.
+        ///
+        /// Besides the core graph item functionality each edge should
+        /// be convertible to the represented undirected edge. 
+        UEdge(const Edge&) {}
+        /// \brief Assign edge to undirected edge.
+        ///
+        /// Besides the core graph item functionality each edge should
+        /// be convertible to the represented undirected edge. 
+        UEdge& operator=(const Edge&) { return *this; }
+      };
+
+      /// \brief Returns the direction of the edge.
+      ///
+      /// Returns the direction of the edge. Each edge represents an
+      /// undirected edge with a direction. It gives back the
+      /// direction.
+      bool direction(const Edge&) const { return true; }
+
+      /// \brief Returns the directed edge.
+      ///
+      /// Returns the directed edge from its direction and the
+      /// represented undirected edge.
+      Edge direct(const UEdge&, bool) const { return INVALID;} 
+
+      /// \brief Returns the directed edge.
+      ///
+      /// Returns the directed edge from its source and the
+      /// represented undirected edge.
+      Edge direct(const UEdge&, const Node&) const { return INVALID;} 
+
+      /// \brief Returns the opposite edge.
+      ///
+      /// Returns the opposite edge. It is the edge representing the
+      /// same undirected edge and has opposite direction.
+      Edge oppositeEdge(const Edge&) const { return INVALID;}
+
+      /// \brief Gives back the target node of an undirected edge.
+      ///
+      /// Gives back the target node of an undirected edge. The name
+      /// target is a little confusing because the undirected edge
+      /// does not have target but it just means that one of the end 
+      /// node.
+      Node target(const UEdge&) const { return INVALID;}
+
+      /// \brief Gives back the source node of an undirected edge.
+      ///
+      /// Gives back the source node of an undirected edge. The name
+      /// source is a little confusing because the undirected edge
+      /// does not have source but it just means that one of the end 
+      /// node.
+      Node source(const UEdge&) const { return INVALID;}
+      
+      template <typename _Graph>
+      struct Constraints {
+	typedef typename _Graph::Node Node;
+	typedef typename _Graph::Edge Edge;
+	typedef typename _Graph::UEdge UEdge;
+      
+	void constraints() {
+          checkConcept<BaseGraphComponent, _Graph>();
+	  checkConcept<GraphItem<'u'>, UEdge>();
+	  {
+	    Node n;
+	    UEdge ue(INVALID);
+            Edge e;
+	    n = graph.source(ue);
+	    n = graph.target(ue);
+            e = graph.direct(ue, true);
+            e = graph.direct(ue, n);
+            e = graph.oppositeEdge(e);
+            ue = e;
+            bool d = graph.direction(e);
+            ignore_unused_variable_warning(d);
+	  }      
+	}
+      
+	const _Graph& graph;
+      };
+
+    };
+
+    /// \brief An empty base bipartite undirected graph class.
+    ///  
+    /// This class provides the minimal set of features needed for an
+    /// bipartite undirected graph structure. All bipartite undirected
+    /// graph concepts have to be conform to this base graph. It just
+    /// provides types for nodes, A-nodes, B-nodes, edges and
+    /// undirected edges and functions to get the source and the
+    /// target of the edges and undirected edges, conversion from
+    /// edges to undirected edges and function to get both direction
+    /// of the undirected edges.
+    class BaseBpUGraphComponent : public BaseUGraphComponent {
+    public:
+      typedef BaseUGraphComponent::Node Node;
+      typedef BaseUGraphComponent::Edge Edge;
+      typedef BaseUGraphComponent::UEdge UEdge;
+
+      /// \brief Helper class for A-nodes.
+      ///
+      /// This class is just a helper class for A-nodes, it is not
+      /// suggested to use it directly. It can be converted easily to
+      /// node and vice versa. The usage of this class is limited
+      /// to use just as template parameters for special map types. 
+      class ANode : public Node {
+      public:
+        typedef Node Parent;
+
+        /// \brief Default constructor.
+        ///      
+        /// \warning The default constructor is not required to set
+        /// the item to some well-defined value. So you should consider it
+        /// as uninitialized.
+        ANode() {}
+        /// \brief Copy constructor.
+        ///
+        /// Copy constructor.
+        ///
+        ANode(const ANode &) : Parent() {}
+        /// \brief Invalid constructor \& conversion.
+        ///
+        /// This constructor initializes the item to be invalid.
+        /// \sa Invalid for more details.
+        ANode(Invalid) {}
+        /// \brief Converter from node to A-node.
+        ///
+        /// Besides the core graph item functionality each node should
+        /// be convertible to the represented A-node if it is it possible. 
+        ANode(const Node&) {}
+        /// \brief Assign node to A-node.
+        ///
+        /// Besides the core graph item functionality each node should
+        /// be convertible to the represented A-node if it is it possible. 
+        ANode& operator=(const Node&) { return *this; }
+      };
+
+      /// \brief Helper class for B-nodes.
+      ///
+      /// This class is just a helper class for B-nodes, it is not
+      /// suggested to use it directly. It can be converted easily to
+      /// node and vice versa. The usage of this class is limited
+      /// to use just as template parameters for special map types. 
+      class BNode : public Node {
+      public:
+        typedef Node Parent;
+
+        /// \brief Default constructor.
+        ///      
+        /// \warning The default constructor is not required to set
+        /// the item to some well-defined value. So you should consider it
+        /// as uninitialized.
+        BNode() {}
+        /// \brief Copy constructor.
+        ///
+        /// Copy constructor.
+        ///
+        BNode(const BNode &) : Parent() {}
+        /// \brief Invalid constructor \& conversion.
+        ///
+        /// This constructor initializes the item to be invalid.
+        /// \sa Invalid for more details.
+        BNode(Invalid) {}
+        /// \brief Converter from node to B-node.
+        ///
+        /// Besides the core graph item functionality each node should
+        /// be convertible to the represented B-node if it is it possible. 
+        BNode(const Node&) {}
+        /// \brief Assign node to B-node.
+        ///
+        /// Besides the core graph item functionality each node should
+        /// be convertible to the represented B-node if it is it possible. 
+        BNode& operator=(const Node&) { return *this; }
+      };
+      
+      /// \brief Gives back %true when the node is A-node.
+      ///
+      /// Gives back %true when the node is A-node.
+      bool aNode(const Node&) const { return false; }
+
+      /// \brief Gives back %true when the node is B-node.
+      ///
+      /// Gives back %true when the node is B-node.
+      bool bNode(const Node&) const { return false; }
+
+      /// \brief Gives back the A-node of the undirected edge.
+      ///
+      /// Gives back the A-node of the undirected edge.
+      Node aNode(const UEdge&) const { return INVALID; }
+
+      /// \brief Gives back the B-node of the undirected edge.
+      ///
+      /// Gives back the B-node of the undirected edge.
+      Node bNode(const UEdge&) const { return INVALID; }
+      
+      template <typename _Graph>
+      struct Constraints {
+	typedef typename _Graph::Node Node;
+	typedef typename _Graph::ANode ANode;
+	typedef typename _Graph::BNode BNode;
+	typedef typename _Graph::Edge Edge;
+	typedef typename _Graph::UEdge UEdge;
+      
+	void constraints() {
+          checkConcept<BaseUGraphComponent, _Graph>();
+	  checkConcept<GraphItem<'a'>, ANode>();
+	  checkConcept<GraphItem<'b'>, BNode>();
+	  {
+	    Node n;
+	    UEdge ue(INVALID);
+            bool b;
+	    n = graph.aNode(ue);
+	    n = graph.bNode(ue);
+            b = graph.aNode(n);
+            b = graph.bNode(n);
+            ANode an;
+            an = n; n = an;
+            BNode bn;
+            bn = n; n = bn;            
+            ignore_unused_variable_warning(b);
+	  }      
+	}
+      
+	const _Graph& graph;
+      };
+
+    };
+
+    /// \brief An empty idable base graph class.
+    ///  
+    /// This class provides beside the core graph features
+    /// core id functions for the graph structure.
+    /// The most of the base graphs should be conform to this concept.
+    /// The id's are unique and immutable.
+    template <typename _Base = BaseGraphComponent>
+    class IDableGraphComponent : public _Base {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+      typedef typename Base::Edge Edge;
+
+      /// \brief Gives back an unique integer id for the Node. 
+      ///
+      /// Gives back an unique integer id for the Node. 
+      ///
+      int id(const Node&) const { return -1;}
+
+      /// \brief Gives back the node by the unique id.
+      ///
+      /// Gives back the node by the unique id.
+      /// If the graph does not contain node with the given id
+      /// then the result of the function is undetermined. 
+      Node nodeFromId(int) const { return INVALID;}
+
+      /// \brief Gives back an unique integer id for the Edge. 
+      ///
+      /// Gives back an unique integer id for the Edge. 
+      ///
+      int id(const Edge&) const { return -1;}
+
+      /// \brief Gives back the edge by the unique id.
+      ///
+      /// Gives back the edge by the unique id.
+      /// If the graph does not contain edge with the given id
+      /// then the result of the function is undetermined. 
+      Edge edgeFromId(int) const { return INVALID;}
+
+      /// \brief Gives back an integer greater or equal to the maximum
+      /// Node id.
+      ///
+      /// Gives back an integer greater or equal to the maximum Node
+      /// id.
+      int maxNodeId() const { return -1;}
+
+      /// \brief Gives back an integer greater or equal to the maximum
+      /// Edge id.
+      ///
+      /// Gives back an integer greater or equal to the maximum Edge
+      /// id.
+      int maxEdgeId() const { return -1;}
+
+      template <typename _Graph>
+      struct Constraints {
+
+	void constraints() {
+	  checkConcept<Base, _Graph >();
+	  typename _Graph::Node node;
+	  int nid = graph.id(node);
+	  nid = graph.id(node);
+	  node = graph.nodeFromId(nid);
+	  typename _Graph::Edge edge;
+	  int eid = graph.id(edge);
+	  eid = graph.id(edge);
+	  edge = graph.edgeFromId(eid);
+
+	  nid = graph.maxNodeId();
+	  ignore_unused_variable_warning(nid);
+	  eid = graph.maxEdgeId();
+	  ignore_unused_variable_warning(eid);
+	}
+
+	const _Graph& graph;
+      };
+    };
+
+    /// \brief An empty idable base undirected graph class.
+    ///  
+    /// This class provides beside the core undirected graph features
+    /// core id functions for the undirected graph structure.  The
+    /// most of the base undirected graphs should be conform to this
+    /// concept.  The id's are unique and immutable.
+    template <typename _Base = BaseUGraphComponent>
+    class IDableUGraphComponent : public IDableGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::UEdge UEdge;
+
+      using IDableGraphComponent<_Base>::id;
+
+      /// \brief Gives back an unique integer id for the UEdge. 
+      ///
+      /// Gives back an unique integer id for the UEdge. 
+      ///
+      int id(const UEdge&) const { return -1;}
+
+      /// \brief Gives back the undirected edge by the unique id.
+      ///
+      /// Gives back the undirected edge by the unique id.  If the
+      /// graph does not contain edge with the given id then the
+      /// result of the function is undetermined.
+      UEdge uEdgeFromId(int) const { return INVALID;}
+
+      /// \brief Gives back an integer greater or equal to the maximum
+      /// UEdge id.
+      ///
+      /// Gives back an integer greater or equal to the maximum UEdge
+      /// id.
+      int maxUEdgeId() const { return -1;}
+
+      template <typename _Graph>
+      struct Constraints {
+
+	void constraints() {
+	  checkConcept<Base, _Graph >();
+	  checkConcept<IDableGraphComponent<Base>, _Graph >();
+	  typename _Graph::UEdge uedge;
+	  int ueid = graph.id(uedge);
+	  ueid = graph.id(uedge);
+	  uedge = graph.uEdgeFromId(ueid);
+	  ueid = graph.maxUEdgeId();
+	  ignore_unused_variable_warning(ueid);
+	}
+
+	const _Graph& graph;
+      };
+    };
+
+    /// \brief An empty idable base bipartite undirected graph class.
+    ///  
+    /// This class provides beside the core bipartite undirected graph
+    /// features core id functions for the bipartite undirected graph
+    /// structure.  The most of the base undirected graphs should be
+    /// conform to this concept.
+    template <typename _Base = BaseBpUGraphComponent>
+    class IDableBpUGraphComponent : public IDableUGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+
+      using IDableUGraphComponent<_Base>::id;
+
+      /// \brief Gives back an unique integer id for the ANode. 
+      ///
+      /// Gives back an unique integer id for the ANode. 
+      ///
+      int aNodeId(const Node&) const { return -1;}
+
+      /// \brief Gives back the undirected edge by the unique id.
+      ///
+      /// Gives back the undirected edge by the unique id.  If the
+      /// graph does not contain edge with the given id then the
+      /// result of the function is undetermined.
+      Node nodeFromANodeId(int) const { return INVALID;}
+
+      /// \brief Gives back an integer greater or equal to the maximum
+      /// ANode id.
+      ///
+      /// Gives back an integer greater or equal to the maximum ANode
+      /// id.
+      int maxANodeId() const { return -1;}
+
+      /// \brief Gives back an unique integer id for the BNode. 
+      ///
+      /// Gives back an unique integer id for the BNode. 
+      ///
+      int bNodeId(const Node&) const { return -1;}
+
+      /// \brief Gives back the undirected edge by the unique id.
+      ///
+      /// Gives back the undirected edge by the unique id.  If the
+      /// graph does not contain edge with the given id then the
+      /// result of the function is undetermined.
+      Node nodeFromBNodeId(int) const { return INVALID;}
+
+      /// \brief Gives back an integer greater or equal to the maximum
+      /// BNode id.
+      ///
+      /// Gives back an integer greater or equal to the maximum BNode
+      /// id.
+      int maxBNodeId() const { return -1;}
+
+      template <typename _Graph>
+      struct Constraints {
+
+	void constraints() {
+	  checkConcept<Base, _Graph >();
+	  checkConcept<IDableGraphComponent<Base>, _Graph >();
+	  typename _Graph::Node node(INVALID);
+	  int id;
+          id = graph.aNodeId(node);
+          id = graph.bNodeId(node);
+          node = graph.nodeFromANodeId(id);
+          node = graph.nodeFromBNodeId(id);
+          id = graph.maxANodeId();
+          id = graph.maxBNodeId();
+	}
+
+	const _Graph& graph;
+      };
+    };
+
+    /// \brief Skeleton class for graph NodeIt and EdgeIt
+    ///
+    /// Skeleton class for graph NodeIt and EdgeIt.
+    ///
+    template <typename _Graph, typename _Item>
+    class GraphItemIt : public _Item {
+    public:
+      /// \brief Default constructor.
+      ///
+      /// @warning The default constructor sets the iterator
+      /// to an undefined value.
+      GraphItemIt() {}
+      /// \brief Copy constructor.
+      ///
+      /// Copy constructor.
+      ///
+      GraphItemIt(const GraphItemIt& ) {}
+      /// \brief Sets the iterator to the first item.
+      ///
+      /// Sets the iterator to the first item of \c the graph.
+      ///
+      explicit GraphItemIt(const _Graph&) {}
+      /// \brief Invalid constructor \& conversion.
+      ///
+      /// This constructor initializes the item to be invalid.
+      /// \sa Invalid for more details.
+      GraphItemIt(Invalid) {}
+      /// \brief Assign operator for items.
+      ///
+      /// The items are assignable. 
+      ///
+      GraphItemIt& operator=(const GraphItemIt&) { return *this; }      
+      /// \brief Next item.
+      /// 
+      /// Assign the iterator to the next item.
+      ///
+      GraphItemIt& operator++() { return *this; }
+      /// \brief Equality operator
+      /// 
+      /// Two iterators are equal if and only if they point to the
+      /// same object or both are invalid.
+      bool operator==(const GraphItemIt&) const { return true;}
+      /// \brief Inequality operator
+      ///	
+      /// \sa operator==(Node n)
+      ///
+      bool operator!=(const GraphItemIt&) const { return true;}
+      
+      template<typename _GraphItemIt>
+      struct Constraints {
+	void constraints() {
+	  _GraphItemIt it1(g);	
+	  _GraphItemIt it2;
+
+	  it2 = ++it1;
+	  ++it2 = it1;
+	  ++(++it1);
+
+	  _Item bi = it1;
+	  bi = it2;
+	}
+	_Graph& g;
+      };
+    };
+
+    /// \brief Skeleton class for graph InEdgeIt and OutEdgeIt
+    ///
+    /// \note Because InEdgeIt and OutEdgeIt may not inherit from the same
+    /// base class, the _selector is a additional template parameter. For 
+    /// InEdgeIt you should instantiate it with character 'i' and for 
+    /// OutEdgeIt with 'o'.
+    template <typename _Graph,
+	      typename _Item = typename _Graph::Edge,
+              typename _Base = typename _Graph::Node, 
+	      char _selector = '0'>
+    class GraphIncIt : public _Item {
+    public:
+      /// \brief Default constructor.
+      ///
+      /// @warning The default constructor sets the iterator
+      /// to an undefined value.
+      GraphIncIt() {}
+      /// \brief Copy constructor.
+      ///
+      /// Copy constructor.
+      ///
+      GraphIncIt(GraphIncIt const& gi) : _Item(gi) {}
+      /// \brief Sets the iterator to the first edge incoming into or outgoing 
+      /// from the node.
+      ///
+      /// Sets the iterator to the first edge incoming into or outgoing 
+      /// from the node.
+      ///
+      explicit GraphIncIt(const _Graph&, const _Base&) {}
+      /// \brief Invalid constructor \& conversion.
+      ///
+      /// This constructor initializes the item to be invalid.
+      /// \sa Invalid for more details.
+      GraphIncIt(Invalid) {}
+      /// \brief Assign operator for iterators.
+      ///
+      /// The iterators are assignable. 
+      ///
+      GraphIncIt& operator=(GraphIncIt const&) { return *this; }      
+      /// \brief Next item.
+      ///
+      /// Assign the iterator to the next item.
+      ///
+      GraphIncIt& operator++() { return *this; }
+
+      /// \brief Equality operator
+      ///
+      /// Two iterators are equal if and only if they point to the
+      /// same object or both are invalid.
+      bool operator==(const GraphIncIt&) const { return true;}
+
+      /// \brief Inequality operator
+      ///
+      /// \sa operator==(Node n)
+      ///
+      bool operator!=(const GraphIncIt&) const { return true;}
+
+      template <typename _GraphIncIt>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<GraphItem<_selector>, _GraphIncIt>();
+	  _GraphIncIt it1(graph, node);
+	  _GraphIncIt it2;
+
+	  it2 = ++it1;
+	  ++it2 = it1;
+	  ++(++it1);
+	  _Item e = it1;
+	  e = it2;
+
+	}
+
+	_Item edge;
+	_Base node;
+	_Graph graph;
+	_GraphIncIt it;
+      };
+    };
+
+
+    /// \brief An empty iterable graph class.
+    ///
+    /// This class provides beside the core graph features
+    /// iterator based iterable interface for the graph structure.
+    /// This concept is part of the Graph concept.
+    template <typename _Base = BaseGraphComponent>
+    class IterableGraphComponent : public _Base {
+
+    public:
+    
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+      typedef typename Base::Edge Edge;
+
+      typedef IterableGraphComponent Graph;
+
+      /// \name Base iteration
+      /// 
+      /// This interface provides functions for iteration on graph items
+      ///
+      /// @{  
+
+      /// \brief Gives back the first node in the iterating order.
+      ///      
+      /// Gives back the first node in the iterating order.
+      ///     
+      void first(Node&) const {}
+
+      /// \brief Gives back the next node in the iterating order.
+      ///
+      /// Gives back the next node in the iterating order.
+      ///     
+      void next(Node&) const {}
+
+      /// \brief Gives back the first edge in the iterating order.
+      ///
+      /// Gives back the first edge in the iterating order.
+      ///     
+      void first(Edge&) const {}
+
+      /// \brief Gives back the next edge in the iterating order.
+      ///
+      /// Gives back the next edge in the iterating order.
+      ///     
+      void next(Edge&) const {}
+
+
+      /// \brief Gives back the first of the edges point to the given
+      /// node.
+      ///
+      /// Gives back the first of the edges point to the given node.
+      ///     
+      void firstIn(Edge&, const Node&) const {}
+
+      /// \brief Gives back the next of the edges points to the given
+      /// node.
+      ///
+      /// Gives back the next of the edges points to the given node.
+      ///
+      void nextIn(Edge&) const {}
+
+      /// \brief Gives back the first of the edges start from the
+      /// given node.
+      ///      
+      /// Gives back the first of the edges start from the given node.
+      ///     
+      void firstOut(Edge&, const Node&) const {}
+
+      /// \brief Gives back the next of the edges start from the given
+      /// node.
+      ///
+      /// Gives back the next of the edges start from the given node.
+      ///     
+      void nextOut(Edge&) const {}
+
+      /// @}
+
+      /// \name Class based iteration
+      /// 
+      /// This interface provides functions for iteration on graph items
+      ///
+      /// @{
+
+      /// \brief This iterator goes through each node.
+      ///
+      /// This iterator goes through each node.
+      ///
+      typedef GraphItemIt<Graph, Node> NodeIt;
+
+      /// \brief This iterator goes through each node.
+      ///
+      /// This iterator goes through each node.
+      ///
+      typedef GraphItemIt<Graph, Edge> EdgeIt;
+
+      /// \brief This iterator goes trough the incoming edges of a node.
+      ///
+      /// This iterator goes trough the \e inccoming edges of a certain node
+      /// of a graph.
+      typedef GraphIncIt<Graph, Edge, Node, 'i'> InEdgeIt;
+
+      /// \brief This iterator goes trough the outgoing edges of a node.
+      ///
+      /// This iterator goes trough the \e outgoing edges of a certain node
+      /// of a graph.
+      typedef GraphIncIt<Graph, Edge, Node, 'o'> OutEdgeIt;
+
+      /// \brief The base node of the iterator.
+      ///
+      /// Gives back the base node of the iterator.
+      /// It is always the target of the pointed edge.
+      Node baseNode(const InEdgeIt&) const { return INVALID; }
+
+      /// \brief The running node of the iterator.
+      ///
+      /// Gives back the running node of the iterator.
+      /// It is always the source of the pointed edge.
+      Node runningNode(const InEdgeIt&) const { return INVALID; }
+
+      /// \brief The base node of the iterator.
+      ///
+      /// Gives back the base node of the iterator.
+      /// It is always the source of the pointed edge.
+      Node baseNode(const OutEdgeIt&) const { return INVALID; }
+
+      /// \brief The running node of the iterator.
+      ///
+      /// Gives back the running node of the iterator.
+      /// It is always the target of the pointed edge.
+      Node runningNode(const OutEdgeIt&) const { return INVALID; }
+
+      /// @}
+
+      template <typename _Graph> 
+      struct Constraints {
+	void constraints() {
+	  checkConcept<Base, _Graph>();
+
+          {
+            typename _Graph::Node node(INVALID);      
+            typename _Graph::Edge edge(INVALID);
+            {
+              graph.first(node);
+              graph.next(node);
+            }
+            {
+              graph.first(edge);
+              graph.next(edge);
+            }
+            {
+              graph.firstIn(edge, node);
+              graph.nextIn(edge);
+            }
+            {
+              graph.firstOut(edge, node);
+              graph.nextOut(edge);
+            }
+          }           
+
+          {
+            checkConcept<GraphItemIt<_Graph, typename _Graph::Edge>,
+              typename _Graph::EdgeIt >();
+            checkConcept<GraphItemIt<_Graph, typename _Graph::Node>,
+              typename _Graph::NodeIt >();
+            checkConcept<GraphIncIt<_Graph, typename _Graph::Edge, 
+              typename _Graph::Node, 'i'>, typename _Graph::InEdgeIt>();
+            checkConcept<GraphIncIt<_Graph, typename _Graph::Edge, 
+              typename _Graph::Node, 'o'>, typename _Graph::OutEdgeIt>();
+
+            typename _Graph::Node n;
+            typename _Graph::InEdgeIt ieit(INVALID);
+            typename _Graph::OutEdgeIt oeit(INVALID);
+            n = graph.baseNode(ieit);
+            n = graph.runningNode(ieit);
+            n = graph.baseNode(oeit);
+            n = graph.runningNode(oeit);
+            ignore_unused_variable_warning(n);
+          }
+        }
+	
+	const _Graph& graph;
+	
+      };
+    };
+
+    /// \brief An empty iterable undirected graph class.
+    ///
+    /// This class provides beside the core graph features iterator
+    /// based iterable interface for the undirected graph structure.
+    /// This concept is part of the UGraph concept.
+    template <typename _Base = BaseUGraphComponent>
+    class IterableUGraphComponent : public IterableGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+      typedef typename Base::Edge Edge;
+      typedef typename Base::UEdge UEdge;
+
+    
+      typedef IterableUGraphComponent Graph;
+
+      /// \name Base iteration
+      /// 
+      /// This interface provides functions for iteration on graph items
+      /// @{  
+
+      using IterableGraphComponent<_Base>::first;
+      using IterableGraphComponent<_Base>::next;
+
+      /// \brief Gives back the first undirected edge in the iterating
+      /// order.
+      ///
+      /// Gives back the first undirected edge in the iterating order.
+      ///     
+      void first(UEdge&) const {}
+
+      /// \brief Gives back the next undirected edge in the iterating
+      /// order.
+      ///
+      /// Gives back the next undirected edge in the iterating order.
+      ///     
+      void next(UEdge&) const {}
+
+
+      /// \brief Gives back the first of the undirected edges from the
+      /// given node.
+      ///
+      /// Gives back the first of the undirected edges from the given
+      /// node. The bool parameter gives back that direction which
+      /// gives a good direction of the uedge so the source of the
+      /// directed edge is the given node.
+      void firstInc(UEdge&, bool&, const Node&) const {}
+
+      /// \brief Gives back the next of the undirected edges from the
+      /// given node.
+      ///
+      /// Gives back the next of the undirected edges from the given
+      /// node. The bool parameter should be used as the \c firstInc()
+      /// use it.
+      void nextInc(UEdge&, bool&) const {}
+
+      using IterableGraphComponent<_Base>::baseNode;
+      using IterableGraphComponent<_Base>::runningNode;
+
+      /// @}
+
+      /// \name Class based iteration
+      /// 
+      /// This interface provides functions for iteration on graph items
+      ///
+      /// @{
+
+      /// \brief This iterator goes through each node.
+      ///
+      /// This iterator goes through each node.
+      typedef GraphItemIt<Graph, UEdge> UEdgeIt;
+      /// \brief This iterator goes trough the incident edges of a
+      /// node.
+      ///
+      /// This iterator goes trough the incident edges of a certain
+      /// node of a graph.
+      typedef GraphIncIt<Graph, UEdge, Node, 'u'> IncEdgeIt;
+      /// \brief The base node of the iterator.
+      ///
+      /// Gives back the base node of the iterator.
+      Node baseNode(const IncEdgeIt&) const { return INVALID; }
+
+      /// \brief The running node of the iterator.
+      ///
+      /// Gives back the running node of the iterator.
+      Node runningNode(const IncEdgeIt&) const { return INVALID; }
+
+      /// @}
+
+      template <typename _Graph> 
+      struct Constraints {
+	void constraints() {
+	  checkConcept<IterableGraphComponent<Base>, _Graph>();
+
+          {
+            typename _Graph::Node node(INVALID);
+            typename _Graph::UEdge uedge(INVALID);
+            bool dir;
+            {
+              graph.first(uedge);
+              graph.next(uedge);
+            }
+            {
+              graph.firstInc(uedge, dir, node);
+              graph.nextInc(uedge, dir);
+            }
+            
+          }	
+  
+          {
+            checkConcept<GraphItemIt<_Graph, typename _Graph::UEdge>,
+              typename _Graph::UEdgeIt >();
+            checkConcept<GraphIncIt<_Graph, typename _Graph::UEdge, 
+              typename _Graph::Node, 'u'>, typename _Graph::IncEdgeIt>();
+            
+            typename _Graph::Node n;
+            typename _Graph::IncEdgeIt ueit(INVALID);
+            n = graph.baseNode(ueit);
+            n = graph.runningNode(ueit);
+          }
+        }
+	
+	const _Graph& graph;
+	
+      };
+    };
+
+    /// \brief An empty iterable bipartite undirected graph class.
+    ///
+    /// This class provides beside the core graph features iterator
+    /// based iterable interface for the bipartite undirected graph
+    /// structure. This concept is part of the BpUGraph concept.
+    template <typename _Base = BaseUGraphComponent>
+    class IterableBpUGraphComponent : public IterableUGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+      typedef typename Base::UEdge UEdge;
+    
+      typedef IterableBpUGraphComponent Graph;
+
+      /// \name Base iteration
+      /// 
+      /// This interface provides functions for iteration on graph items
+      /// @{  
+
+      using IterableUGraphComponent<_Base>::first;
+      using IterableUGraphComponent<_Base>::next;
+
+      /// \brief Gives back the first A-node in the iterating order.
+      ///
+      /// Gives back the first undirected A-node in the iterating
+      /// order.
+      ///     
+      void firstANode(Node&) const {}
+
+      /// \brief Gives back the next A-node in the iterating order.
+      ///
+      /// Gives back the next A-node in the iterating order.
+      ///     
+      void nextANode(Node&) const {}
+
+      /// \brief Gives back the first B-node in the iterating order.
+      ///
+      /// Gives back the first undirected B-node in the iterating
+      /// order.
+      ///     
+      void firstBNode(Node&) const {}
+
+      /// \brief Gives back the next B-node in the iterating order.
+      ///
+      /// Gives back the next B-node in the iterating order.
+      ///     
+      void nextBNode(Node&) const {}
+
+
+      /// \brief Gives back the first of the undirected edges start
+      /// from the given A-node.
+      ///      
+      /// Gives back the first of the undirected edges start from the
+      /// given A-node.
+      void firstFromANode(UEdge&, const Node&) const {}
+
+      /// \brief Gives back the next of the undirected edges start
+      /// from the given A-node.
+      ///      
+      /// Gives back the next of the undirected edges start from the
+      /// given A-node.
+      void nextFromANode(UEdge&) const {}
+
+      /// \brief Gives back the first of the undirected edges start
+      /// from the given B-node.
+      ///      
+      /// Gives back the first of the undirected edges start from the
+      /// given B-node.
+      void firstFromBNode(UEdge&, const Node&) const {}
+
+      /// \brief Gives back the next of the undirected edges start
+      /// from the given B-node.
+      ///      
+      /// Gives back the next of the undirected edges start from the
+      /// given B-node.
+      void nextFromBNode(UEdge&) const {}
+
+
+      /// @}
+
+      /// \name Class based iteration
+      /// 
+      /// This interface provides functions for iteration on graph items
+      ///
+      /// @{
+
+      /// \brief This iterator goes through each A-node.
+      ///
+      /// This iterator goes through each A-node.
+      typedef GraphItemIt<Graph, Node> ANodeIt;
+
+      /// \brief This iterator goes through each B-node.
+      ///
+      /// This iterator goes through each B-node.
+      typedef GraphItemIt<Graph, Node> BNodeIt;
+
+      /// @}
+
+      template <typename _Graph> 
+      struct Constraints {
+	void constraints() {
+	  checkConcept<IterableUGraphComponent<Base>, _Graph>();
+
+          {
+            typename _Graph::Node node(INVALID);
+            typename _Graph::UEdge uedge(INVALID);
+            graph.firstANode(node);
+            graph.nextANode(node);
+            graph.firstBNode(node);
+            graph.nextBNode(node);
+
+            graph.firstFromANode(uedge, node);
+            graph.nextFromANode(uedge);
+            graph.firstFromBNode(uedge, node);
+            graph.nextFromBNode(uedge);
+          }
+          {
+            checkConcept<GraphItemIt<_Graph, typename _Graph::Node>,
+              typename _Graph::ANodeIt >();
+            checkConcept<GraphItemIt<_Graph, typename _Graph::Node>,
+              typename _Graph::BNodeIt >();
+          }
+
+	}
+	
+	const _Graph& graph;
+	
+      };
+    };
+
+    /// \brief An empty alteration notifier graph class.
+    ///  
+    /// This class provides beside the core graph features alteration
+    /// notifier interface for the graph structure.  This implements
+    /// an observer-notifier pattern for each graph item. More
+    /// obsevers can be registered into the notifier and whenever an
+    /// alteration occured in the graph all the observers will
+    /// notified about it.
+    template <typename _Base = BaseGraphComponent>
+    class AlterableGraphComponent : public _Base {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+      typedef typename Base::Edge Edge;
+
+
+      /// The node observer registry.
+      typedef AlterationNotifier<AlterableGraphComponent, Node> 
+      NodeNotifier;
+      /// The edge observer registry.
+      typedef AlterationNotifier<AlterableGraphComponent, Edge> 
+      EdgeNotifier;
+      
+      /// \brief Gives back the node alteration notifier.
+      ///
+      /// Gives back the node alteration notifier.
+      NodeNotifier& getNotifier(Node) const {
+	return NodeNotifier();
+      }
+      
+      /// \brief Gives back the edge alteration notifier.
+      ///
+      /// Gives back the edge alteration notifier.
+      EdgeNotifier& getNotifier(Edge) const {
+	return EdgeNotifier();
+      }
+
+      template <typename _Graph> 
+      struct Constraints {
+	void constraints() {
+	  checkConcept<Base, _Graph>();
+          typename _Graph::NodeNotifier& nn 
+            = graph.getNotifier(typename _Graph::Node());
+
+          typename _Graph::EdgeNotifier& en 
+            = graph.getNotifier(typename _Graph::Edge());
+          
+          ignore_unused_variable_warning(nn);
+          ignore_unused_variable_warning(en);
+	}
+	
+	const _Graph& graph;
+	
+      };
+      
+    };
+
+    /// \brief An empty alteration notifier undirected graph class.
+    ///  
+    /// This class provides beside the core graph features alteration
+    /// notifier interface for the graph structure.  This implements
+    /// an observer-notifier pattern for each graph item. More
+    /// obsevers can be registered into the notifier and whenever an
+    /// alteration occured in the graph all the observers will
+    /// notified about it.
+    template <typename _Base = BaseUGraphComponent>
+    class AlterableUGraphComponent : public AlterableGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::UEdge UEdge;
+
+
+      /// The edge observer registry.
+      typedef AlterationNotifier<AlterableUGraphComponent, UEdge> 
+      UEdgeNotifier;
+      
+      /// \brief Gives back the edge alteration notifier.
+      ///
+      /// Gives back the edge alteration notifier.
+      UEdgeNotifier& getNotifier(UEdge) const {
+	return UEdgeNotifier();
+      }
+
+      template <typename _Graph> 
+      struct Constraints {
+	void constraints() {
+	  checkConcept<AlterableGraphComponent<Base>, _Graph>();
+          typename _Graph::UEdgeNotifier& uen 
+            = graph.getNotifier(typename _Graph::UEdge());
+          ignore_unused_variable_warning(uen);
+	}
+	
+	const _Graph& graph;
+	
+      };
+      
+    };
+
+    /// \brief An empty alteration notifier bipartite undirected graph
+    /// class.
+    ///  
+    /// This class provides beside the core graph features alteration
+    /// notifier interface for the graph structure.  This implements
+    /// an observer-notifier pattern for each graph item. More
+    /// obsevers can be registered into the notifier and whenever an
+    /// alteration occured in the graph all the observers will
+    /// notified about it.
+    template <typename _Base = BaseUGraphComponent>
+    class AlterableBpUGraphComponent : public AlterableUGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::ANode ANode;
+      typedef typename Base::BNode BNode;
+
+
+      /// The A-node observer registry.
+      typedef AlterationNotifier<AlterableBpUGraphComponent, ANode> 
+      ANodeNotifier;
+
+      /// The B-node observer registry.
+      typedef AlterationNotifier<AlterableBpUGraphComponent, BNode> 
+      BNodeNotifier;
+      
+      /// \brief Gives back the A-node alteration notifier.
+      ///
+      /// Gives back the A-node alteration notifier.
+      ANodeNotifier& getNotifier(ANode) const {
+	return ANodeNotifier();
+      }
+
+      /// \brief Gives back the B-node alteration notifier.
+      ///
+      /// Gives back the B-node alteration notifier.
+      BNodeNotifier& getNotifier(BNode) const {
+	return BNodeNotifier();
+      }
+
+      template <typename _Graph> 
+      struct Constraints {
+	void constraints() {
+          checkConcept<AlterableUGraphComponent<Base>, _Graph>();
+          typename _Graph::ANodeNotifier& ann 
+            = graph.getNotifier(typename _Graph::ANode());
+          typename _Graph::BNodeNotifier& bnn 
+            = graph.getNotifier(typename _Graph::BNode());
+          ignore_unused_variable_warning(ann);
+          ignore_unused_variable_warning(bnn);
+	}
+	
+	const _Graph& graph;
+	
+      };
+      
+    };
+
+
+    /// \brief Class describing the concept of graph maps
+    /// 
+    /// This class describes the common interface of the graph maps
+    /// (NodeMap, EdgeMap), that is \ref maps-page "maps" which can be used to
+    /// associate data to graph descriptors (nodes or edges).
+    template <typename _Graph, typename _Item, typename _Value>
+    class GraphMap : public ReadWriteMap<_Item, _Value> {
+    public:
+
+      typedef ReadWriteMap<_Item, _Value> Parent;
+
+      /// The graph type of the map.
+      typedef _Graph Graph;
+      /// The key type of the map.
+      typedef _Item Key;
+      /// The value type of the map.
+      typedef _Value Value;
+
+      /// \brief Construct a new map.
+      ///
+      /// Construct a new map for the graph.
+      explicit GraphMap(const Graph&) {}
+      /// \brief Construct a new map with default value.
+      ///
+      /// Construct a new map for the graph and initalise the values.
+      GraphMap(const Graph&, const Value&) {}
+      /// \brief Copy constructor.
+      ///
+      /// Copy Constructor.
+      GraphMap(const GraphMap&) : Parent() {}
+      
+      /// \brief Assign operator.
+      ///
+      /// Assign operator. It does not mofify the underlying graph,
+      /// it just iterates on the current item set and set the  map
+      /// with the value returned by the assigned map. 
+      template <typename CMap>
+      GraphMap& operator=(const CMap&) { 
+        checkConcept<ReadMap<Key, Value>, CMap>();
+        return *this;
+      }
+
+      template<typename _Map>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<ReadWriteMap<Key, Value>, _Map >();
+	  // Construction with a graph parameter
+	  _Map a(g);
+	  // Constructor with a graph and a default value parameter
+	  _Map a2(g,t);
+	  // Copy constructor.
+	  _Map b(c);
+          
+          ReadMap<Key, Value> cmap;
+          b = cmap;
+
+	  ignore_unused_variable_warning(a2);
+	  ignore_unused_variable_warning(b);
+	}
+
+	const _Map &c;
+	const Graph &g;
+	const typename GraphMap::Value &t;
+      };
+
+    };
+
+    /// \brief An empty mappable graph class.
+    ///
+    /// This class provides beside the core graph features
+    /// map interface for the graph structure.
+    /// This concept is part of the Graph concept.
+    template <typename _Base = BaseGraphComponent>
+    class MappableGraphComponent : public _Base  {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+      typedef typename Base::Edge Edge;
+
+      typedef MappableGraphComponent Graph;
+
+      /// \brief ReadWrite map of the nodes.
+      ///
+      /// ReadWrite map of the nodes.
+      ///
+      template <typename _Value>
+      class NodeMap : public GraphMap<Graph, Node, _Value> {
+      private:
+	NodeMap();
+      public:
+        typedef GraphMap<MappableGraphComponent, Node, _Value> Parent;
+
+	/// \brief Construct a new map.
+	///
+	/// Construct a new map for the graph.
+	/// \todo call the right parent class constructor
+	explicit NodeMap(const MappableGraphComponent& graph) 
+          : Parent(graph) {}
+
+	/// \brief Construct a new map with default value.
+	///
+	/// Construct a new map for the graph and initalise the values.
+	NodeMap(const MappableGraphComponent& graph, const _Value& value)
+          : Parent(graph, value) {}
+
+	/// \brief Copy constructor.
+	///
+	/// Copy Constructor.
+	NodeMap(const NodeMap& nm) : Parent(nm) {}
+
+	/// \brief Assign operator.
+	///
+	/// Assign operator.
+        template <typename CMap>
+        NodeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Node, _Value>, CMap>();
+          return *this;
+        }
+
+      };
+
+      /// \brief ReadWrite map of the edges.
+      ///
+      /// ReadWrite map of the edges.
+      ///
+      template <typename _Value>
+      class EdgeMap : public GraphMap<Graph, Edge, _Value> {
+      private:
+	EdgeMap();
+      public:
+        typedef GraphMap<MappableGraphComponent, Edge, _Value> Parent;
+
+	/// \brief Construct a new map.
+	///
+	/// Construct a new map for the graph.
+	/// \todo call the right parent class constructor
+	explicit EdgeMap(const MappableGraphComponent& graph) 
+          : Parent(graph) {}
+
+	/// \brief Construct a new map with default value.
+	///
+	/// Construct a new map for the graph and initalise the values.
+	EdgeMap(const MappableGraphComponent& graph, const _Value& value)
+          : Parent(graph, value) {}
+
+	/// \brief Copy constructor.
+	///
+	/// Copy Constructor.
+	EdgeMap(const EdgeMap& nm) : Parent(nm) {}
+
+	/// \brief Assign operator.
+	///
+	/// Assign operator.
+        template <typename CMap>
+        EdgeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Edge, _Value>, CMap>();
+          return *this;
+        }
+
+      };
+
+
+      template <typename _Graph>
+      struct Constraints {
+
+	struct Dummy {
+	  int value;
+	  Dummy() : value(0) {}
+	  Dummy(int _v) : value(_v) {}
+	};
+
+	void constraints() {
+	  checkConcept<Base, _Graph>();
+	  { // int map test
+	    typedef typename _Graph::template NodeMap<int> IntNodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Node, int>, 
+	      IntNodeMap >();
+	  } { // bool map test
+	    typedef typename _Graph::template NodeMap<bool> BoolNodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Node, bool>,
+	      BoolNodeMap >();
+	  } { // Dummy map test
+	    typedef typename _Graph::template NodeMap<Dummy> DummyNodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Node, Dummy>,
+	      DummyNodeMap >();
+	  } 
+
+	  { // int map test
+	    typedef typename _Graph::template EdgeMap<int> IntEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, int>,
+	      IntEdgeMap >();
+	  } { // bool map test
+	    typedef typename _Graph::template EdgeMap<bool> BoolEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, bool>,
+	      BoolEdgeMap >();
+	  } { // Dummy map test
+	    typedef typename _Graph::template EdgeMap<Dummy> DummyEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, Dummy>, 
+	      DummyEdgeMap >();
+	  } 
+	}
+
+	_Graph& graph;
+      };
+    };
+
+    /// \brief An empty mappable base bipartite undirected graph class.
+    ///
+    /// This class provides beside the core graph features
+    /// map interface for the graph structure.
+    /// This concept is part of the UGraph concept.
+    template <typename _Base = BaseUGraphComponent>
+    class MappableUGraphComponent : public MappableGraphComponent<_Base>  {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::UEdge UEdge;
+
+      typedef MappableUGraphComponent Graph;
+
+      /// \brief ReadWrite map of the uedges.
+      ///
+      /// ReadWrite map of the uedges.
+      ///
+      template <typename _Value>
+      class UEdgeMap : public GraphMap<Graph, UEdge, _Value> {  
+      public:
+        typedef GraphMap<MappableUGraphComponent, UEdge, _Value> Parent;
+
+	/// \brief Construct a new map.
+	///
+	/// Construct a new map for the graph.
+	/// \todo call the right parent class constructor
+	explicit UEdgeMap(const MappableUGraphComponent& graph) 
+          : Parent(graph) {}
+
+	/// \brief Construct a new map with default value.
+	///
+	/// Construct a new map for the graph and initalise the values.
+	UEdgeMap(const MappableUGraphComponent& graph, const _Value& value)
+          : Parent(graph, value) {}
+
+	/// \brief Copy constructor.
+	///
+	/// Copy Constructor.
+	UEdgeMap(const UEdgeMap& nm) : Parent(nm) {}
+
+	/// \brief Assign operator.
+	///
+	/// Assign operator.
+        template <typename CMap>
+        UEdgeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<UEdge, _Value>, CMap>();
+          return *this;
+        }
+
+      };
+
+
+      template <typename _Graph>
+      struct Constraints {
+
+	struct Dummy {
+	  int value;
+	  Dummy() : value(0) {}
+	  Dummy(int _v) : value(_v) {}
+	};
+
+	void constraints() {
+	  checkConcept<MappableGraphComponent<Base>, _Graph>();
+
+	  { // int map test
+	    typedef typename _Graph::template UEdgeMap<int> IntUEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, int>,
+	      IntUEdgeMap >();
+	  } { // bool map test
+	    typedef typename _Graph::template UEdgeMap<bool> BoolUEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, bool>,
+	      BoolUEdgeMap >();
+	  } { // Dummy map test
+	    typedef typename _Graph::template UEdgeMap<Dummy> DummyUEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, Dummy>, 
+	      DummyUEdgeMap >();
+	  } 
+	}
+
+	_Graph& graph;
+      };
+    };
+
+    /// \brief An empty mappable base bipartite undirected graph
+    /// class.
+    ///
+    /// This class provides beside the core graph features
+    /// map interface for the graph structure.
+    /// This concept is part of the BpUGraph concept.
+    template <typename _Base = BaseBpUGraphComponent>
+    class MappableBpUGraphComponent : public MappableUGraphComponent<_Base>  {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+
+      typedef MappableBpUGraphComponent Graph;
+
+      /// \brief ReadWrite map of the A-nodes.
+      ///
+      /// ReadWrite map of the A-nodes.
+      ///
+      template <typename _Value>
+      class ANodeMap : public GraphMap<Graph, Node, _Value> {  
+      public:
+        typedef GraphMap<MappableBpUGraphComponent, Node, _Value> Parent;
+
+	/// \brief Construct a new map.
+	///
+	/// Construct a new map for the graph.
+	/// \todo call the right parent class constructor
+	explicit ANodeMap(const MappableBpUGraphComponent& graph) 
+          : Parent(graph) {}
+
+	/// \brief Construct a new map with default value.
+	///
+	/// Construct a new map for the graph and initalise the values.
+	ANodeMap(const MappableBpUGraphComponent& graph, const _Value& value)
+          : Parent(graph, value) {}
+
+	/// \brief Copy constructor.
+	///
+	/// Copy Constructor.
+	ANodeMap(const ANodeMap& nm) : Parent(nm) {}
+
+	/// \brief Assign operator.
+	///
+	/// Assign operator.
+        template <typename CMap>
+        ANodeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Node, _Value>, CMap>();
+          return *this;
+        }
+
+      };
+
+      /// \brief ReadWrite map of the B-nodes.
+      ///
+      /// ReadWrite map of the A-nodes.
+      ///
+      template <typename _Value>
+      class BNodeMap : public GraphMap<Graph, Node, _Value> {  
+      public:
+        typedef GraphMap<MappableBpUGraphComponent, Node, _Value> Parent;
+
+	/// \brief Construct a new map.
+	///
+	/// Construct a new map for the graph.
+	/// \todo call the right parent class constructor
+	explicit BNodeMap(const MappableBpUGraphComponent& graph) 
+          : Parent(graph) {}
+
+	/// \brief Construct a new map with default value.
+	///
+	/// Construct a new map for the graph and initalise the values.
+	BNodeMap(const MappableBpUGraphComponent& graph, const _Value& value)
+          : Parent(graph, value) {}
+
+	/// \brief Copy constructor.
+	///
+	/// Copy Constructor.
+	BNodeMap(const BNodeMap& nm) : Parent(nm) {}
+
+	/// \brief Assign operator.
+	///
+	/// Assign operator.
+        template <typename CMap>
+        BNodeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Node, _Value>, CMap>();
+          return *this;
+        }
+
+      };
+
+
+      template <typename _Graph>
+      struct Constraints {
+
+	struct Dummy {
+	  int value;
+	  Dummy() : value(0) {}
+	  Dummy(int _v) : value(_v) {}
+	};
+
+	void constraints() {
+	  checkConcept<MappableUGraphComponent<Base>, _Graph>();
+
+	  { // int map test
+	    typedef typename _Graph::template ANodeMap<int> IntANodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::ANode, int>,
+	      IntANodeMap >();
+	  } { // bool map test
+	    typedef typename _Graph::template ANodeMap<bool> BoolANodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::ANode, bool>,
+	      BoolANodeMap >();
+	  } { // Dummy map test
+	    typedef typename _Graph::template ANodeMap<Dummy> DummyANodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::ANode, Dummy>, 
+	      DummyANodeMap >();
+	  } 
+	}
+
+	_Graph& graph;
+      };
+    };
+
+
+    /// \brief An empty extendable graph class.
+    ///
+    /// This class provides beside the core graph features graph
+    /// extendable interface for the graph structure.  The main
+    /// difference between the base and this interface is that the
+    /// graph alterations should handled already on this level.
+    template <typename _Base = BaseGraphComponent>
+    class ExtendableGraphComponent : public _Base {
+    public:
+      typedef _Base Base;
+
+      typedef typename _Base::Node Node;
+      typedef typename _Base::Edge Edge;
+
+      /// \brief Adds a new node to the graph.
+      ///
+      /// Adds a new node to the graph.
+      ///
+      Node addNode() {
+	return INVALID;
+      }
+    
+      /// \brief Adds a new edge connects the given two nodes.
+      ///
+      /// Adds a new edge connects the the given two nodes.
+      Edge addEdge(const Node&, const Node&) {
+	return INVALID;
+      }
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+          checkConcept<Base, _Graph>();
+	  typename _Graph::Node node_a, node_b;
+	  node_a = graph.addNode();
+	  node_b = graph.addNode();
+	  typename _Graph::Edge edge;
+	  edge = graph.addEdge(node_a, node_b);
+	}
+
+	_Graph& graph;
+      };
+    };
+
+    /// \brief An empty extendable base undirected graph class.
+    ///
+    /// This class provides beside the core undirected graph features
+    /// core undircted graph extend interface for the graph structure.
+    /// The main difference between the base and this interface is
+    /// that the graph alterations should handled already on this
+    /// level.
+    template <typename _Base = BaseUGraphComponent>
+    class ExtendableUGraphComponent : public _Base {
+    public:
+
+      typedef _Base Base;
+      typedef typename _Base::Node Node;
+      typedef typename _Base::UEdge UEdge;
+
+      /// \brief Adds a new node to the graph.
+      ///
+      /// Adds a new node to the graph.
+      ///
+      Node addNode() {
+	return INVALID;
+      }
+    
+      /// \brief Adds a new edge connects the given two nodes.
+      ///
+      /// Adds a new edge connects the the given two nodes.
+      UEdge addEdge(const Node&, const Node&) {
+	return INVALID;
+      }
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<Base, _Graph>();
+	  typename _Graph::Node node_a, node_b;
+	  node_a = graph.addNode();
+	  node_b = graph.addNode();
+	  typename _Graph::UEdge uedge;
+	  uedge = graph.addUEdge(node_a, node_b);
+	}
+
+	_Graph& graph;
+      };
+    };
+
+    /// \brief An empty extendable base undirected graph class.
+    ///
+    /// This class provides beside the core bipartite undirected graph
+    /// features core undircted graph extend interface for the graph
+    /// structure.  The main difference between the base and this
+    /// interface is that the graph alterations should handled already
+    /// on this level.
+    template <typename _Base = BaseBpUGraphComponent>
+    class ExtendableBpUGraphComponent 
+      : public ExtendableUGraphComponent<_Base> {
+
+      typedef _Base Base;
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+          checkConcept<ExtendableUGraphComponent<Base>, _Graph>();
+	}
+      };
+    };
+
+    /// \brief An empty erasable graph class.
+    ///  
+    /// This class provides beside the core graph features core erase
+    /// functions for the graph structure. The main difference between
+    /// the base and this interface is that the graph alterations
+    /// should handled already on this level.
+    template <typename _Base = BaseGraphComponent>
+    class ErasableGraphComponent : public _Base {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+      typedef typename Base::Edge Edge;
+
+      /// \brief Erase a node from the graph.
+      ///
+      /// Erase a node from the graph. This function should 
+      /// erase all edges connecting to the node.
+      void erase(const Node&) {}    
+
+      /// \brief Erase an edge from the graph.
+      ///
+      /// Erase an edge from the graph.
+      ///
+      void erase(const Edge&) {}
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+          checkConcept<Base, _Graph>();
+	  typename _Graph::Node node;
+	  graph.erase(node);
+	  typename _Graph::Edge edge;
+	  graph.erase(edge);
+	}
+
+	_Graph& graph;
+      };
+    };
+
+    /// \brief An empty erasable base undirected graph class.
+    ///  
+    /// This class provides beside the core undirected graph features
+    /// core erase functions for the undirceted graph structure. The
+    /// main difference between the base and this interface is that
+    /// the graph alterations should handled already on this level.
+    template <typename _Base = BaseUGraphComponent>
+    class ErasableUGraphComponent : public _Base {
+    public:
+
+      typedef _Base Base;
+      typedef typename Base::Node Node;
+      typedef typename Base::UEdge UEdge;
+
+      /// \brief Erase a node from the graph.
+      ///
+      /// Erase a node from the graph. This function should erase
+      /// edges connecting to the node.
+      void erase(const Node&) {}    
+
+      /// \brief Erase an edge from the graph.
+      ///
+      /// Erase an edge from the graph.
+      ///
+      void erase(const UEdge&) {}
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+          checkConcept<Base, _Graph>();
+	  typename _Graph::Node node;
+	  graph.erase(node);
+	  typename _Graph::Edge edge;
+	  graph.erase(edge);
+	}
+
+	_Graph& graph;
+      };
+    };
+
+    /// \brief An empty erasable base bipartite undirected graph class.
+    ///  
+    /// This class provides beside the core bipartite undirected graph
+    /// features core erase functions for the undirceted graph
+    /// structure. The main difference between the base and this
+    /// interface is that the graph alterations should handled already
+    /// on this level.
+    template <typename _Base = BaseBpUGraphComponent>
+    class ErasableBpUGraphComponent : public ErasableUGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+          checkConcept<ErasableUGraphComponent<Base>, _Graph>();
+	}
+      };
+    };
+
+    /// \brief An empty clearable base graph class.
+    ///
+    /// This class provides beside the core graph features core clear
+    /// functions for the graph structure. The main difference between
+    /// the base and this interface is that the graph alterations
+    /// should handled already on this level.
+    template <typename _Base = BaseGraphComponent>
+    class ClearableGraphComponent : public _Base {
+    public:
+
+      typedef _Base Base;
+
+      /// \brief Erase all nodes and edges from the graph.
+      ///
+      /// Erase all nodes and edges from the graph.
+      ///
+      void clear() {}    
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+          checkConcept<Base, _Graph>();
+	  graph.clear();
+	}
+
+	_Graph graph;
+      };
+    };
+
+    /// \brief An empty clearable base undirected graph class.
+    ///
+    /// This class provides beside the core undirected graph features
+    /// core clear functions for the undirected graph structure. The
+    /// main difference between the base and this interface is that
+    /// the graph alterations should handled already on this level.
+    template <typename _Base = BaseUGraphComponent>
+    class ClearableUGraphComponent : public ClearableUGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+          checkConcept<ClearableUGraphComponent<Base>, _Graph>();
+	}
+
+	_Graph graph;
+      };
+    };
+
+    /// \brief An empty clearable base bipartite undirected graph
+    /// class.
+    ///
+    /// This class provides beside the core bipartite undirected graph
+    /// features core clear functions for the undirected graph
+    /// structure. The main difference between the base and this
+    /// interface is that the graph alterations should handled already
+    /// on this level.
+    template <typename _Base = BaseUGraphComponent>
+    class ClearableBpUGraphComponent 
+      : public ClearableBpUGraphComponent<_Base> {
+    public:
+
+      typedef _Base Base;
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+          checkConcept<ClearableBpUGraphComponent<Base>, _Graph>();
+	}
+
+      };
+
+    };
+
+  }
+
+}
+
+#endif
Index: lemon/concepts/heap.h
===================================================================
--- lemon/concepts/heap.h	(revision 2260)
+++ lemon/concepts/heap.h	(revision 2260)
@@ -0,0 +1,223 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2006
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+///\ingroup concept
+///\file
+///\brief Classes for representing heaps.
+///
+
+#ifndef LEMON_CONCEPT_HEAP_H
+#define LEMON_CONCEPT_HEAP_H
+
+#include <lemon/bits/invalid.h>
+
+namespace lemon {
+  namespace concepts {
+    /// \addtogroup concept
+    /// @{
+
+
+    /// \brief A concept structure describes the main interface of heaps.
+    ///
+    /// A concept structure describes the main interface of heaps.
+    ///
+    template <typename Item, typename Prio, typename ItemIntMap>
+    class Heap {
+    public:
+  
+
+      /// \brief Type to represent the items states.
+      ///
+      /// Each Item element have a state associated to it. It may be "in heap",
+      /// "pre heap" or "post heap". The later two are indifferent from the
+      /// heap's point of view, but may be useful to the user.
+      ///
+      /// The ItemIntMap _should_ be initialized in such way, that it maps
+      /// PRE_HEAP (-1) to any element to be put in the heap...
+      enum state_enum {
+	IN_HEAP = 0,
+	PRE_HEAP = -1,
+	POST_HEAP = -2
+      };
+      
+      /// \brief The constructor.
+      ///
+      /// The constructor.
+      /// \param _iim should be given to the constructor, since it is used
+      /// internally to handle the cross references. The value of the map
+      /// should be PRE_HEAP (-1) for each element.
+      explicit Heap(ItemIntMap &_iim) {}
+
+      /// \brief The number of items stored in the heap.
+      ///
+      /// Returns the number of items stored in the heap.
+      int size() const { return 0; }
+
+      /// \brief Checks if the heap stores no items.
+      ///
+      /// Returns \c true if and only if the heap stores no items.
+      bool empty() const { return false; }
+
+      /// \brief Makes empty this heap.
+      ///
+      /// Makes this heap empty.
+      void clear();
+
+      /// \brief Insert an item into the heap with the given heap.
+      ///    
+      /// Adds \c i to the heap with priority \c p. 
+      /// \param i The item to insert.
+      /// \param p The priority of the item.
+      void push(const Item &i, const Prio &p) {}
+
+      /// \brief Returns the item with minimum priority.
+      ///
+      /// This method returns the item with minimum priority.  
+      /// \pre The heap must be nonempty.  
+      Item top() const {}
+
+      /// \brief Returns the minimum priority.
+      ///
+      /// It returns the minimum priority.
+      /// \pre The heap must be nonempty.
+      Prio prio() const {}
+
+      /// \brief Deletes the item with minimum priority.
+      ///
+      /// This method deletes the item with minimum priority.
+      /// \pre The heap must be non-empty.  
+      void pop() {}
+
+      /// \brief Deletes \c i from the heap.
+      ///
+      /// This method deletes item \c i from the heap, if \c i was
+      /// already stored in the heap.
+      /// \param i The item to erase. 
+      void erase(const Item &i) {}
+
+      /// \brief Returns the priority of \c i.
+      ///
+      /// This function returns the priority of item \c i.  
+      /// \pre \c i must be in the heap.
+      /// \param i The item.
+      Prio operator[](const Item &i) const {}
+
+      /// \brief \c i gets to the heap with priority \c p independently 
+      /// if \c i was already there.
+      ///
+      /// This method calls \ref push(\c i, \c p) if \c i is not stored
+      /// in the heap and sets the priority of \c i to \c p otherwise.
+      /// It may throw an \e UnderFlowPriorityException. 
+      /// \param i The item.
+      /// \param p The priority.
+      void set(const Item &i, const Prio &p) {}
+      
+      /// \brief Decreases the priority of \c i to \c p.
+      ///
+      /// This method decreases the priority of item \c i to \c p.
+      /// \pre \c i must be stored in the heap with priority at least \c p.
+      /// \param i The item.
+      /// \param p The priority.
+      void decrease(const Item &i, const Prio &p) {}
+
+      /// \brief Increases the priority of \c i to \c p.
+      ///
+      /// This method sets the priority of item \c i to \c p. 
+      /// \pre \c i must be stored in the heap with priority at most \c
+      /// p relative to \c Compare.
+      /// \param i The item.
+      /// \param p The priority.
+      void increase(const Item &i, const Prio &p) {}
+
+      /// \brief Returns if \c item is in, has already been in, or has 
+      /// never been in the heap.
+      ///
+      /// This method returns PRE_HEAP if \c item has never been in the
+      /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
+      /// otherwise. In the latter case it is possible that \c item will
+      /// get back to the heap again.
+      /// \param i The item.
+      state_enum state(const Item &i) const {}
+
+      /// \brief Sets the state of the \c item in the heap.
+      ///
+      /// Sets the state of the \c item in the heap. It can be used to
+      /// manually clear the heap when it is important to achive the
+      /// better time complexity.
+      /// \param i The item.
+      /// \param st The state. It should not be \c IN_HEAP. 
+      void state(const Item& i, state_enum st) {}
+
+
+      template <typename _Heap>
+      struct Constraints {
+      public:
+    
+	void constraints() {
+	  Item item;
+	  Prio prio;
+
+	  item=Item();
+	  prio=Prio();
+
+	  ignore_unused_variable_warning(item);
+	  ignore_unused_variable_warning(prio);
+
+	  typedef typename _Heap::state_enum state_enum;
+	  state_enum state;
+
+	  ignore_unused_variable_warning(state);
+      
+	  _Heap heap1 = _Heap(map);
+
+	  ignore_unused_variable_warning(heap1);
+      
+	  heap.push(item, prio);
+
+	  prio = heap.prio();
+	  item = heap.top();
+
+	  heap.pop();
+
+	  heap.set(item, prio);
+	  heap.decrease(item, prio);
+	  heap.increase(item, prio);
+	  prio = heap[item];
+
+	  heap.erase(item);
+
+	  state = heap.state(item);
+
+	  state = _Heap::PRE_HEAP;
+	  state = _Heap::IN_HEAP;
+	  state = _Heap::POST_HEAP;
+
+	  heap.clear();
+	}
+    
+	_Heap& heap;
+	ItemIntMap& map;
+
+	Constraints() : heap(0), map(0) {}
+      };
+    };
+
+    /// @}
+  } // namespace lemon
+}
+#endif // LEMON_CONCEPT_PATH_H
Index: lemon/concepts/maps.h
===================================================================
--- lemon/concepts/maps.h	(revision 2260)
+++ lemon/concepts/maps.h	(revision 2260)
@@ -0,0 +1,192 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2006
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#ifndef LEMON_CONCEPT_MAPS_H
+#define LEMON_CONCEPT_MAPS_H
+
+#include <lemon/bits/utility.h>
+#include <lemon/concept_check.h>
+
+///\ingroup concept
+///\file
+///\brief Map concepts checking classes for testing and documenting.
+
+namespace lemon {
+
+  namespace concepts {
+  
+    /// \addtogroup concept
+    /// @{
+
+    /// Readable map concept
+    template<typename K, typename T>
+    class ReadMap
+    {
+    public:
+      /// Map's key type.
+      typedef K Key;    
+      /// Map's value type. (The type of objects associated with the keys).
+      typedef T Value;
+
+      // \bug Value don't need to be default constructible.
+      /// Returns the value associated with a key.
+      Value operator[](const Key &) const {return Value();}
+
+      template<typename _ReadMap>
+      struct Constraints {
+
+	void constraints() {
+	  Value val = m[key];
+	  val = m[key];
+	  typename _ReadMap::Value own_val = m[own_key]; 
+	  own_val = m[own_key]; 
+
+	  ignore_unused_variable_warning(val);
+	  ignore_unused_variable_warning(own_val);
+	  ignore_unused_variable_warning(key);
+	}
+	Key& key;
+	typename _ReadMap::Key& own_key;
+	_ReadMap& m;
+      };
+      
+    };
+
+
+    /// Writable map concept
+    template<typename K, typename T>
+    class WriteMap
+    {
+    public:
+      /// Map's key type.
+      typedef K Key;    
+      /// Map's value type. (The type of objects associated with the keys).
+      typedef T Value;
+
+      /// Sets the value associated with a key.
+      void set(const Key &,const Value &) {}
+
+      ///Default constructor
+      WriteMap() {}
+
+      template <typename _WriteMap>
+      struct Constraints {
+	void constraints() {
+	  // No constraints for constructor.
+	  m.set(key, val);
+	  m.set(own_key, own_val);
+	  ignore_unused_variable_warning(key);
+	  ignore_unused_variable_warning(val);
+	  ignore_unused_variable_warning(own_key);
+	  ignore_unused_variable_warning(own_val);
+	}
+
+	Value& val;
+	typename _WriteMap::Value own_val;
+	Key& key;
+	typename _WriteMap::Key& own_key;
+	_WriteMap& m;
+
+      };
+    };
+
+    ///Read/Writable map concept
+    template<typename K, typename T>
+    class ReadWriteMap : public ReadMap<K,T>,
+			    public WriteMap<K,T>
+    {
+    public:
+      /// Map's key type.
+      typedef K Key;    
+      /// Map's value type. (The type of objects associated with the keys).
+      typedef T Value;
+
+      /// Returns the value associated with a key.
+      Value operator[](const Key &) const {return Value();}
+      /// Sets the value associated with a key.
+      void set(const Key & ,const Value &) {}
+
+      template<typename _ReadWriteMap>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<ReadMap<K, T>, _ReadWriteMap >();
+	  checkConcept<WriteMap<K, T>, _ReadWriteMap >();
+	}
+      };
+    };
+  
+  
+    ///Dereferable map concept
+    template<typename K, typename T, typename R, typename CR>
+    class ReferenceMap : public ReadWriteMap<K,T>
+    {
+    public:
+      /// Tag for reference maps.
+      typedef True ReferenceMapTag;
+      /// Map's key type.
+      typedef K Key;    
+      /// Map's value type. (The type of objects associated with the keys).
+      typedef T Value;
+      /// Map's reference type.
+      typedef R Reference;
+      /// Map's const reference type.
+      typedef CR ConstReference;
+
+    protected:
+      Value tmp;
+    public:
+
+      ///Returns a reference to the value associated to a key.
+      Reference operator[](const Key &) { return tmp; }
+      ///Returns a const reference to the value associated to a key.
+      ConstReference operator[](const Key &) const
+      { return tmp; }
+      /// Sets the value associated with a key.
+      void set(const Key &k,const Value &t) { operator[](k)=t; }
+
+      // \todo rethink this concept
+      template<typename _ReferenceMap>
+      struct ReferenceMapConcept {
+
+	void constraints() {
+	  checkConcept<ReadWriteMap, _ReferenceMap >();
+	  m[key] = val;
+	  val  = m[key];
+	  m[key] = ref;
+	  ref = m[key];
+	  m[own_key] = own_val;
+	  own_val  = m[own_key];
+	  m[own_key] = own_ref;
+	  own_ref = m[own_key];	  	  
+	}
+
+	typename _ReferenceMap::Key& own_key;
+	typename _ReferenceMap::Value& own_val;
+	typename _ReferenceMap::Reference& own_ref;
+	Key& key;
+	Value& val;
+	Reference& ref;
+	_ReferenceMap& m;
+      };
+    };
+
+    // @}
+
+  } //namespace concepts
+} //namespace lemon
+#endif // LEMON_CONCEPT_MAPS_H
Index: lemon/concepts/matrix_maps.h
===================================================================
--- lemon/concepts/matrix_maps.h	(revision 2260)
+++ lemon/concepts/matrix_maps.h	(revision 2260)
@@ -0,0 +1,207 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2006
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#ifndef LEMON_CONCEPT_MATRIX_MAPS_H
+#define LEMON_CONCEPT_MATRIX_MAPS_H
+
+#include <lemon/bits/utility.h>
+#include <lemon/concept_check.h>
+
+///\ingroup concept
+///\file
+///\brief MatrixMap concepts checking classes for testing and documenting.
+
+namespace lemon {
+
+  namespace concepts {
+  
+    /// \addtogroup concept
+    /// @{
+
+    /// Readable matrix map concept
+    template <typename K1, typename K2, typename V>
+    class ReadMatrixMap
+    {
+    public:
+      /// Map's first key type.
+      typedef K1 FirstKey;    
+      /// Map's second key type.
+      typedef K2 SecondKey;    
+      /// \brief Map's value type. 
+      /// (The type of objects associated with the pairs of keys).
+      typedef V Value;
+
+      // \bug Value don't need to be default constructible.
+      /// Returns the value associated with a key.
+      Value operator()(const FirstKey&, const SecondKey&) const {
+	return Value();
+      }
+
+      template <typename _ReadMatrixMap>
+      struct Constraints {
+
+	void constraints() {
+	  Value val = m(first_key, second_key);
+	  val = m(first_key, second_key);
+	  typename _ReadMatrixMap::Value own_val = 
+	    m(own_first_key, own_second_key); 
+	  own_val = m(own_first_key, own_second_key);
+	  ignore_unused_variable_warning(val);
+	  ignore_unused_variable_warning(own_val);
+	}
+
+	FirstKey& first_key;
+	SecondKey& second_key;	
+	typename _ReadMatrixMap::FirstKey& own_first_key;
+	typename _ReadMatrixMap::SecondKey& own_second_key;
+	_ReadMatrixMap& m;
+      };
+      
+    };
+
+
+    /// Writable map concept
+    template <typename K1, typename K2, typename V>
+    class WriteMatrixMap {
+    public:
+      /// Map's first key type.
+      typedef K1 FirstKey;    
+      /// Map's second key type.
+      typedef K2 SecondKey;    
+      /// \brief Map's value type. 
+      /// (The type of objects associated with the pairs of keys).
+      typedef V Value;
+
+      /// Sets the value associated with the pair of keys.
+      void set(const FirstKey&, const SecondKey& ,const Value&) {}
+
+      template <typename _WriteMatrixMap>
+      struct Constraints {
+	void constraints() {
+	  // No constraints for constructor.
+	  m.set(first_key, second_key, val);
+	  m.set(own_first_key, own_second_key, own_val);
+	}
+
+	Value& val;
+	typename _WriteMatrixMap::Value own_val;
+	FirstKey& first_key;
+	SecondKey& second_key;
+	typename _WriteMatrixMap::FirstKey& own_first_key;
+	typename _WriteMatrixMap::SecondKey& own_second_key;
+	_WriteMatrixMap& m;
+
+      };
+    };
+
+    ///Read/Writable map concept
+    template<typename K1, typename K2, typename V>
+    class ReadWriteMatrixMap 
+      : public ReadMatrixMap<K1, K2, V>, public WriteMatrixMap<K1, K2, V> {
+    public:
+      /// Map's first key type.
+      typedef K1 FirstKey;    
+      /// Map's second key type.
+      typedef K2 SecondKey;    
+      /// \brief Map's value type. 
+      /// (The type of objects associated with the pairs of keys).
+      typedef V Value;
+
+      /// Returns the value associated with a pair of keys.
+      Value operator()(const FirstKey&, const SecondKey&) const { 
+	return Value(); 
+      }
+      /// Sets the value associated with the pair of keys.
+      void set(const FirstKey&, const SecondKey& ,const Value&) {}
+
+      template<typename _ReadWriteMatrixMap>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<ReadMatrixMap<K1, K2, V>, _ReadWriteMatrixMap >();
+	  checkConcept<WriteMatrixMap<K1, K2, V>, _ReadWriteMatrixMap >();
+	}
+      };
+    };
+  
+  
+    ///Dereferable matrix map concept
+    template<typename K1, typename K2, typename V, typename R, typename CR>
+    class ReferenceMatrixMap : public ReadWriteMatrixMap<K1, K2, V>
+    {
+    public:
+      /// Tag for reference maps.
+      typedef True ReferenceMapTag;
+      /// Map's first key type.
+      typedef K1 FirstKey;    
+      /// Map's second key type.
+      typedef K1 SecondKey;    
+      /// Map's value type. (The type of objects associated with the keys).
+      typedef V Value;
+      /// Map's reference type.
+      typedef R Reference;
+      /// Map's const reference type.
+      typedef CR ConstReference;
+
+    protected:
+      Value tmp;
+    public:
+
+      ///Returns a reference to the value associated to a pair of keys.
+      Reference operator()(const FirstKey&, const SecondKey&) { 
+	return tmp; 
+      }
+      ///Returns a const reference to the value associated to a pair of keys.
+      ConstReference operator()(const FirstKey&, const SecondKey&) const { 
+	return tmp; 
+      }
+      /// Sets the value associated with the pair of keys.
+      void set(const FirstKey&, const SecondKey& ,const Value&) {}
+
+      // \todo rethink this concept
+      template<typename _ReferenceMatrixMap>
+      struct ReferenceMapConcept {
+
+	void constraints() {
+	  checkConcept<ReadWriteMatrixMap, _ReferenceMatrixMap >();
+	  m(first_key, second_key) = val;
+	  val  = m(first_key, second_key);
+	  m(first_key, second_key) = ref;
+	  ref = m(first_key, second_key);
+	  m(own_first_key, own_second_key) = own_val;
+	  own_val  = m(own_first_key, own_second_key);
+	  m(own_first_key, own_second_key) = own_ref;
+	  own_ref = m(own_first_key, own_second_key); 
+	}
+
+	typename _ReferenceMatrixMap::Key& own_first_key;
+	typename _ReferenceMatrixMap::Key& own_second_key;
+	typename _ReferenceMatrixMap::Value& own_val;
+	typename _ReferenceMatrixMap::Reference& own_ref;
+	FirstKey& first_key;
+	SecondKey& second_key;
+	Value& val;
+	Reference& ref;
+	_ReferenceMatrixMap& m;
+      };
+    };
+
+    // @}
+
+  } //namespace concepts
+} //namespace lemon
+#endif // LEMON_CONCEPT_MATRIX_MAPS_H
Index: lemon/concepts/path.h
===================================================================
--- lemon/concepts/path.h	(revision 2260)
+++ lemon/concepts/path.h	(revision 2260)
@@ -0,0 +1,294 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2006
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+///\ingroup concept
+///\file
+///\brief Classes for representing paths in graphs.
+///
+///\todo Iterators have obsolete style
+
+#ifndef LEMON_CONCEPT_PATH_H
+#define LEMON_CONCEPT_PATH_H
+
+#include <lemon/bits/invalid.h>
+#include <lemon/concept_check.h>
+
+namespace lemon {
+  namespace concepts {
+    /// \addtogroup concept
+    /// @{
+
+
+    //! \brief A skeleton structure for representing directed paths in a graph.
+    //!
+    //! A skeleton structure for representing directed paths in a graph.
+    //! \param _Graph The graph type in which the path is.
+    //!
+    //! In a sense, the path can be treated as a graph, for it has \c NodeIt
+    //! and \c EdgeIt with the same usage. These types converts to the \c Node
+    //! and \c Edge of the original graph.
+    template<typename _Graph>
+    class Path {
+    public:
+
+      /// Type of the underlying graph.
+      typedef _Graph Graph;
+      /// Edge type of the underlying graph.
+      typedef typename Graph::Edge Edge;
+      /// Node type of the underlying graph.
+      typedef typename Graph::Node Node;
+
+      class NodeIt;
+      class EdgeIt;
+
+      /// \param _g The graph in which the path is.
+      ///
+      Path(const Graph &_g) {
+	ignore_unused_variable_warning(_g);
+      }
+
+      /// Length of the path ie. the number of edges in the path.
+      int length() const {return 0;}
+
+      /// Returns whether the path is empty.
+      bool empty() const { return true;}
+
+      /// Resets the path to an empty path.
+      void clear() {}
+
+      /// \brief Starting point of the path.
+      ///
+      /// Starting point of the path.
+      /// Returns INVALID if the path is empty.
+      Node target() const {return INVALID;}
+      /// \brief End point of the path.
+      ///
+      /// End point of the path.
+      /// Returns INVALID if the path is empty.
+      Node source() const {return INVALID;}
+
+      /// \brief The target of an edge.
+      ///
+      /// Returns node iterator pointing to the target node of the
+      /// given edge iterator.
+      NodeIt target(const EdgeIt&) const {return INVALID;}
+
+      /// \brief The source of an edge.
+      ///
+      /// Returns node iterator pointing to the source node of the
+      /// given edge iterator.
+      NodeIt source(const EdgeIt&) const {return INVALID;}
+
+      /// \brief Iterator class to iterate on the nodes of the paths
+      ///
+      /// This class is used to iterate on the nodes of the paths
+      ///
+      /// Of course it converts to Graph::Node.
+      class NodeIt {
+      public:
+	/// Default constructor
+	NodeIt() {}
+	/// Invalid constructor
+	NodeIt(Invalid) {}
+	/// Constructor with starting point
+	NodeIt(const Path &) {}
+
+	///Conversion to Graph::Node
+	operator Node() const { return INVALID; }
+	/// Next node
+	NodeIt& operator++() {return *this;}
+
+	/// Comparison operator
+	bool operator==(const NodeIt&) const {return true;}
+	/// Comparison operator
+	bool operator!=(const NodeIt&) const {return true;}
+ 	/// Comparison operator
+ 	bool operator<(const NodeIt&) const {return false;}
+
+      };
+
+      /// \brief Iterator class to iterate on the edges of the paths
+      ///
+      /// This class is used to iterate on the edges of the paths
+      ///
+      /// Of course it converts to Graph::Edge
+      class EdgeIt {
+      public:
+	/// Default constructor
+	EdgeIt() {}
+	/// Invalid constructor
+	EdgeIt(Invalid) {}
+	/// Constructor with starting point
+	EdgeIt(const Path &) {}
+
+	operator Edge() const { return INVALID; }
+
+	/// Next edge
+	EdgeIt& operator++() {return *this;}
+
+	/// Comparison operator
+	bool operator==(const EdgeIt&) const {return true;}
+	/// Comparison operator
+	bool operator!=(const EdgeIt&) const {return true;}
+ 	/// Comparison operator
+ 	bool operator<(const EdgeIt&) const {return false;}
+
+      };
+
+
+      friend class Builder;
+
+      /// \brief Class to build paths
+      ///
+      /// This class is used to fill a path with edges.
+      ///
+      /// You can push new edges to the front and to the back of the path in
+      /// arbitrary order then you should commit these changes to the graph.
+      ///
+      /// While the builder is active (after the first modifying
+      /// operation and until the call of \ref commit()) the
+      /// underlining Path is in a "transitional" state (operations on
+      /// it have undefined result).
+      class Builder {
+      public:
+
+        /// Constructor
+
+        /// Constructor
+	/// \param _path the path you want to fill in.
+	///
+
+	Builder(Path &_path) { ignore_unused_variable_warning(_path); }
+
+	/// Sets the starting node of the path.
+
+	/// Sets the starting node of the path. Edge added to the path
+	/// afterwards have to be incident to this node.
+	/// You \em must start building an empty path with these functions.
+	/// (And you \em must \em not use it later).
+	/// \sa pushFront()
+	/// \sa pushBack()
+	void setStartNode(const Node &) {}
+
+	///Push a new edge to the front of the path
+
+	///Push a new edge to the front of the path.
+	///If the path is empty, you \em must call \ref setStartNode() before
+	///the first use of \ref pushFront().
+	void pushFront(const Edge&) {}
+
+	///Push a new edge to the back of the path
+
+	///Push a new edge to the back of the path.
+	///If the path is empty, you \em must call \ref setStartNode() before
+	///the first use of \ref pushBack().
+	void pushBack(const Edge&) {}
+
+	///Commit the changes to the path.
+
+	///Commit the changes to the path.
+        ///
+	void commit() {}
+
+	///Reserve (front) storage for the builder in advance.
+
+	///If you know a reasonable upper bound on the number of the edges
+	///to add to the front of the path,
+	///using this function you may speed up the building.
+	void reserveFront(size_t) {}
+	///Reserve (back) storage for the builder in advance.
+
+	///If you know a reasonable upper bound on the number of the edges
+	///to add to the back of the path,
+	///using this function you may speed up the building.
+	void reserveBack(size_t) {}
+      };
+
+      template <typename _Path>
+      struct Constraints {
+	void constraints() {
+          typedef typename _Path::Node Node;
+          typedef typename _Path::NodeIt NodeIt;
+          typedef typename Graph::Node GraphNode;
+
+          typedef typename _Path::Edge Edge;
+          typedef typename _Path::EdgeIt EdgeIt;
+          typedef typename Graph::Edge GraphEdge;
+
+          typedef typename _Path::Builder Builder;
+
+          path = _Path(graph);
+
+          bool b = cpath.empty();
+          int l = cpath.length();
+
+          Node gn;
+          Edge ge;
+          gn = cpath.source();
+          gn = cpath.target();
+
+          NodeIt nit;
+          EdgeIt eit(INVALID);
+          nit = path.source(eit);
+          nit = path.target(eit);
+          
+          nit = NodeIt();
+          nit = NodeIt(cpath);
+          nit = INVALID;
+          gn = nit;
+          ++nit;
+          b = nit == nit;
+          b = nit != nit;
+          b = nit < nit;
+
+          eit = EdgeIt();
+          eit = EdgeIt(cpath);
+          eit = INVALID;
+          ge = eit;
+          ++eit;
+          b = eit == eit;
+          b = eit != eit;
+          b = eit < eit;
+
+          size_t st = 0;
+
+          Builder builder(path); 
+          builder.setStartNode(gn);
+          builder.pushFront(ge);
+          builder.pushBack(ge);
+          builder.commit();
+          builder.reserveFront(st);
+          builder.reserveBack(st);
+          
+          ignore_unused_variable_warning(l);
+          ignore_unused_variable_warning(b);
+	}
+
+        const Graph& graph;
+        const _Path& cpath;
+        _Path& path;
+      };
+
+    };
+
+  ///@}
+  }
+
+} // namespace lemon
+
+#endif // LEMON_CONCEPT_PATH_H
Index: lemon/concepts/ugraph.h
===================================================================
--- lemon/concepts/ugraph.h	(revision 2260)
+++ lemon/concepts/ugraph.h	(revision 2260)
@@ -0,0 +1,713 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2006
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+///\ingroup graph_concepts
+///\file
+///\brief The concept of the undirected graphs.
+
+
+#ifndef LEMON_CONCEPT_UGRAPH_H
+#define LEMON_CONCEPT_UGRAPH_H
+
+#include <lemon/concepts/graph_components.h>
+#include <lemon/concepts/graph.h>
+#include <lemon/bits/utility.h>
+
+namespace lemon {
+  namespace concepts {
+
+    /// \addtogroup graph_concepts
+    /// @{
+
+
+    /// \brief Class describing the concept of Undirected Graphs.
+    ///
+    /// This class describes the common interface of all Undirected
+    /// Graphs.
+    ///
+    /// As all concept describing classes it provides only interface
+    /// without any sensible implementation. So any algorithm for
+    /// undirected graph should compile with this class, but it will not
+    /// run properly, of course.
+    ///
+    /// The LEMON undirected graphs also fulfill the concept of
+    /// directed graphs (\ref lemon::concepts::Graph "Graph
+    /// Concept"). Each undirected edges can be seen as two opposite
+    /// directed edge and consequently the undirected graph can be
+    /// seen as the direceted graph of these directed edges. The
+    /// UGraph has the UEdge inner class for the undirected edges and
+    /// the Edge type for the directed edges. The Edge type is
+    /// convertible to UEdge or inherited from it so from a directed
+    /// edge we can get the represented undirected edge.
+    ///
+    /// In the sense of the LEMON each undirected edge has a default
+    /// direction (it should be in every computer implementation,
+    /// because the order of undirected edge's nodes defines an
+    /// orientation). With the default orientation we can define that
+    /// the directed edge is forward or backward directed. With the \c
+    /// direction() and \c direct() function we can get the direction
+    /// of the directed edge and we can direct an undirected edge.
+    ///
+    /// The UEdgeIt is an iterator for the undirected edges. We can use
+    /// the UEdgeMap to map values for the undirected edges. The InEdgeIt and
+    /// OutEdgeIt iterates on the same undirected edges but with opposite
+    /// direction. The IncEdgeIt iterates also on the same undirected edges
+    /// as the OutEdgeIt and InEdgeIt but it is not convertible to Edge just
+    /// to UEdge.  
+    class UGraph {
+    public:
+      /// \brief The undirected graph should be tagged by the
+      /// UndirectedTag.
+      ///
+      /// The undirected graph should be tagged by the UndirectedTag. This
+      /// tag helps the enable_if technics to make compile time 
+      /// specializations for undirected graphs.  
+      typedef True UndirectedTag;
+
+      /// \brief The base type of node iterators, 
+      /// or in other words, the trivial node iterator.
+      ///
+      /// This is the base type of each node iterator,
+      /// thus each kind of node iterator converts to this.
+      /// More precisely each kind of node iterator should be inherited 
+      /// from the trivial node iterator.
+      class Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        Node() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        Node(const Node&) { }
+
+        /// Invalid constructor \& conversion.
+
+        /// This constructor initializes the iterator to be invalid.
+        /// \sa Invalid for more details.
+        Node(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(Node) const { return true; }
+
+        /// Inequality operator
+        
+        /// \sa operator==(Node n)
+        ///
+        bool operator!=(Node) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(Node) const { return false; }
+
+      };
+    
+      /// This iterator goes through each node.
+
+      /// This iterator goes through each node.
+      /// Its usage is quite simple, for example you can count the number
+      /// of nodes in graph \c g of type \c Graph like this:
+      ///\code
+      /// int count=0;
+      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
+      ///\endcode
+      class NodeIt : public Node {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        NodeIt() { }
+        /// Copy constructor.
+        
+        /// Copy constructor.
+        ///
+        NodeIt(const NodeIt& n) : Node(n) { }
+        /// Invalid constructor \& conversion.
+
+        /// Initialize the iterator to be invalid.
+        /// \sa Invalid for more details.
+        NodeIt(Invalid) { }
+        /// Sets the iterator to the first node.
+
+        /// Sets the iterator to the first node of \c g.
+        ///
+        NodeIt(const UGraph&) { }
+        /// Node -> NodeIt conversion.
+
+        /// Sets the iterator to the node of \c the graph pointed by 
+	/// the trivial iterator.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        NodeIt(const UGraph&, const Node&) { }
+        /// Next node.
+
+        /// Assign the iterator to the next node.
+        ///
+        NodeIt& operator++() { return *this; }
+      };
+    
+    
+      /// The base type of the undirected edge iterators.
+
+      /// The base type of the undirected edge iterators.
+      ///
+      class UEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        UEdge() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        UEdge(const UEdge&) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        UEdge(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(UEdge) const { return true; }
+        /// Inequality operator
+
+        /// \sa operator==(UEdge n)
+        ///
+        bool operator!=(UEdge) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(UEdge) const { return false; }
+      };
+
+      /// This iterator goes through each undirected edge.
+
+      /// This iterator goes through each undirected edge of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of undirected edges in a graph \c g of type \c Graph as follows:
+      ///\code
+      /// int count=0;
+      /// for(Graph::UEdgeIt e(g); e!=INVALID; ++e) ++count;
+      ///\endcode
+      class UEdgeIt : public UEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        UEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        UEdgeIt(const UEdgeIt& e) : UEdge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        UEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first undirected edge.
+    
+        /// This constructor sets the iterator to the first undirected edge.
+        UEdgeIt(const UGraph&) { }
+        /// UEdge -> UEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator.
+        /// This feature necessitates that each time we
+        /// iterate the undirected edge-set, the iteration order is the 
+	/// same.
+        UEdgeIt(const UGraph&, const UEdge&) { } 
+        /// Next undirected edge
+        
+        /// Assign the iterator to the next undirected edge.
+        UEdgeIt& operator++() { return *this; }
+      };
+
+      /// \brief This iterator goes trough the incident undirected 
+      /// edges of a node.
+      ///
+      /// This iterator goes trough the incident undirected edges
+      /// of a certain node of a graph. You should assume that the 
+      /// loop edges will be iterated twice.
+      /// 
+      /// Its usage is quite simple, for example you can compute the
+      /// degree (i.e. count the number of incident edges of a node \c n
+      /// in graph \c g of type \c Graph as follows. 
+      ///
+      ///\code
+      /// int count=0;
+      /// for(Graph::IncEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      ///\endcode
+      class IncEdgeIt : public UEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        IncEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        IncEdgeIt(const IncEdgeIt& e) : UEdge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        IncEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to first incident edge.
+    
+        /// This constructor set the iterator to the first incident edge of
+        /// the node.
+        IncEdgeIt(const UGraph&, const Node&) { }
+        /// UEdge -> IncEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        IncEdgeIt(const UGraph&, const UEdge&) { }
+        /// Next incident edge
+
+        /// Assign the iterator to the next incident edge
+	/// of the corresponding node.
+        IncEdgeIt& operator++() { return *this; }
+      };
+
+      /// The directed edge type.
+
+      /// The directed edge type. It can be converted to the
+      /// undirected edge or it should be inherited from the undirected
+      /// edge.
+      class Edge : public UEdge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        Edge() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        Edge(const Edge& e) : UEdge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        Edge(Invalid) { }
+        /// Equality operator
+
+        /// Two iterators are equal if and only if they point to the
+        /// same object or both are invalid.
+        bool operator==(Edge) const { return true; }
+        /// Inequality operator
+
+        /// \sa operator==(Edge n)
+        ///
+        bool operator!=(Edge) const { return true; }
+
+	/// Artificial ordering operator.
+	
+	/// To allow the use of graph descriptors as key type in std::map or
+	/// similar associative container we require this.
+	///
+	/// \note This operator only have to define some strict ordering of
+	/// the items; this order has nothing to do with the iteration
+	/// ordering of the items.
+	bool operator<(Edge) const { return false; }
+	
+      }; 
+      /// This iterator goes through each directed edge.
+
+      /// This iterator goes through each edge of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of edges in a graph \c g of type \c Graph as follows:
+      ///\code
+      /// int count=0;
+      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
+      ///\endcode
+      class EdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        EdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        EdgeIt(const EdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        EdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first edge.
+    
+        /// This constructor sets the iterator to the first edge of \c g.
+        ///@param g the graph
+        EdgeIt(const UGraph &g) { ignore_unused_variable_warning(g); }
+        /// Edge -> EdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        EdgeIt(const UGraph&, const Edge&) { } 
+        ///Next edge
+        
+        /// Assign the iterator to the next edge.
+        EdgeIt& operator++() { return *this; }
+      };
+   
+      /// This iterator goes trough the outgoing directed edges of a node.
+
+      /// This iterator goes trough the \e outgoing edges of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of outgoing edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      ///\code
+      /// int count=0;
+      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      ///\endcode
+    
+      class OutEdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        OutEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        OutEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to the first outgoing edge.
+    
+        /// This constructor sets the iterator to the first outgoing edge of
+        /// the node.
+        ///@param n the node
+        ///@param g the graph
+        OutEdgeIt(const UGraph& n, const Node& g) {
+	  ignore_unused_variable_warning(n);
+	  ignore_unused_variable_warning(g);
+	}
+        /// Edge -> OutEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator.
+	/// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        OutEdgeIt(const UGraph&, const Edge&) { }
+        ///Next outgoing edge
+        
+        /// Assign the iterator to the next 
+        /// outgoing edge of the corresponding node.
+        OutEdgeIt& operator++() { return *this; }
+      };
+
+      /// This iterator goes trough the incoming directed edges of a node.
+
+      /// This iterator goes trough the \e incoming edges of a certain node
+      /// of a graph.
+      /// Its usage is quite simple, for example you can count the number
+      /// of outgoing edges of a node \c n
+      /// in graph \c g of type \c Graph as follows.
+      ///\code
+      /// int count=0;
+      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
+      ///\endcode
+
+      class InEdgeIt : public Edge {
+      public:
+        /// Default constructor
+
+        /// @warning The default constructor sets the iterator
+        /// to an undefined value.
+        InEdgeIt() { }
+        /// Copy constructor.
+
+        /// Copy constructor.
+        ///
+        InEdgeIt(const InEdgeIt& e) : Edge(e) { }
+        /// Initialize the iterator to be invalid.
+
+        /// Initialize the iterator to be invalid.
+        ///
+        InEdgeIt(Invalid) { }
+        /// This constructor sets the iterator to first incoming edge.
+    
+        /// This constructor set the iterator to the first incoming edge of
+        /// the node.
+        ///@param n the node
+        ///@param g the graph
+        InEdgeIt(const UGraph& g, const Node& n) { 
+	  ignore_unused_variable_warning(n);
+	  ignore_unused_variable_warning(g);
+	}
+        /// Edge -> InEdgeIt conversion
+
+        /// Sets the iterator to the value of the trivial iterator \c e.
+        /// This feature necessitates that each time we 
+        /// iterate the edge-set, the iteration order is the same.
+        InEdgeIt(const UGraph&, const Edge&) { }
+        /// Next incoming edge
+
+        /// Assign the iterator to the next inedge of the corresponding node.
+        ///
+        InEdgeIt& operator++() { return *this; }
+      };
+
+      /// \brief Read write map of the nodes to type \c T.
+      /// 
+      /// ReadWrite map of the nodes to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (NodeMap<bool>)
+      /// needs some extra attention!
+      template<class T> 
+      class NodeMap : public ReadWriteMap< Node, T >
+      {
+      public:
+
+        ///\e
+        NodeMap(const UGraph&) { }
+        ///\e
+        NodeMap(const UGraph&, T) { }
+
+        ///Copy constructor
+        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }
+        ///Assignment operator
+        template <typename CMap>
+        NodeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Node, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// \brief Read write map of the directed edges to type \c T.
+      ///
+      /// Reference map of the directed edges to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (EdgeMap<bool>)
+      /// needs some extra attention!
+      template<class T> 
+      class EdgeMap : public ReadWriteMap<Edge,T>
+      {
+      public:
+
+        ///\e
+        EdgeMap(const UGraph&) { }
+        ///\e
+        EdgeMap(const UGraph&, T) { }
+        ///Copy constructor
+        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }
+        ///Assignment operator
+        template <typename CMap>
+        EdgeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<Edge, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// Read write map of the undirected edges to type \c T.
+
+      /// Reference map of the edges to type \c T.
+      /// \sa Reference
+      /// \warning Making maps that can handle bool type (UEdgeMap<bool>)
+      /// needs some extra attention!
+      template<class T> 
+      class UEdgeMap : public ReadWriteMap<UEdge,T>
+      {
+      public:
+
+        ///\e
+        UEdgeMap(const UGraph&) { }
+        ///\e
+        UEdgeMap(const UGraph&, T) { }
+        ///Copy constructor
+        UEdgeMap(const UEdgeMap& em) : ReadWriteMap<UEdge,T>(em) {}
+        ///Assignment operator
+        template <typename CMap>
+        UEdgeMap& operator=(const CMap&) { 
+          checkConcept<ReadMap<UEdge, T>, CMap>();
+          return *this; 
+        }
+      };
+
+      /// \brief Direct the given undirected edge.
+      ///
+      /// Direct the given undirected edge. The returned edge source
+      /// will be the given node.
+      Edge direct(const UEdge&, const Node&) const {
+	return INVALID;
+      }
+
+      /// \brief Direct the given undirected edge.
+      ///
+      /// Direct the given undirected edge. The returned edge
+      /// represents the given undireted edge and the direction comes
+      /// from the given bool.  The source of the undirected edge and
+      /// the directed edge is the same when the given bool is true.
+      Edge direct(const UEdge&, bool) const {
+	return INVALID;
+      }
+
+      /// \brief Returns true if the edge has default orientation.
+      ///
+      /// Returns whether the given directed edge is same orientation as
+      /// the corresponding undirected edge's default orientation.
+      bool direction(Edge) const { return true; }
+
+      /// \brief Returns the opposite directed edge.
+      ///
+      /// Returns the opposite directed edge.
+      Edge oppositeEdge(Edge) const { return INVALID; }
+
+      /// \brief Opposite node on an edge
+      ///
+      /// \return the opposite of the given Node on the given UEdge
+      Node oppositeNode(Node, UEdge) const { return INVALID; }
+
+      /// \brief First node of the undirected edge.
+      ///
+      /// \return the first node of the given UEdge.
+      ///
+      /// Naturally undirected edges don't have direction and thus
+      /// don't have source and target node. But we use these two methods
+      /// to query the two nodes of the edge. The direction of the edge
+      /// which arises this way is called the inherent direction of the
+      /// undirected edge, and is used to define the "default" direction
+      /// of the directed versions of the edges.
+      /// \sa direction
+      Node source(UEdge) const { return INVALID; }
+
+      /// \brief Second node of the undirected edge.
+      Node target(UEdge) const { return INVALID; }
+
+      /// \brief Source node of the directed edge.
+      Node source(Edge) const { return INVALID; }
+
+      /// \brief Target node of the directed edge.
+      Node target(Edge) const { return INVALID; }
+
+      void first(Node&) const {}
+      void next(Node&) const {}
+
+      void first(UEdge&) const {}
+      void next(UEdge&) const {}
+
+      void first(Edge&) const {}
+      void next(Edge&) const {}
+
+      void firstOut(Edge&, Node) const {}
+      void nextOut(Edge&) const {}
+
+      void firstIn(Edge&, Node) const {}
+      void nextIn(Edge&) const {}
+
+
+      void firstInc(UEdge &, bool &, const Node &) const {}
+      void nextInc(UEdge &, bool &) const {}
+
+      /// \brief Base node of the iterator
+      ///
+      /// Returns the base node (the source in this case) of the iterator
+      Node baseNode(OutEdgeIt e) const {
+	return source(e);
+      }
+      /// \brief Running node of the iterator
+      ///
+      /// Returns the running node (the target in this case) of the
+      /// iterator
+      Node runningNode(OutEdgeIt e) const {
+	return target(e);
+      }
+
+      /// \brief Base node of the iterator
+      ///
+      /// Returns the base node (the target in this case) of the iterator
+      Node baseNode(InEdgeIt e) const {
+	return target(e);
+      }
+      /// \brief Running node of the iterator
+      ///
+      /// Returns the running node (the source in this case) of the
+      /// iterator
+      Node runningNode(InEdgeIt e) const {
+	return source(e);
+      }
+
+      /// \brief Base node of the iterator
+      ///
+      /// Returns the base node of the iterator
+      Node baseNode(IncEdgeIt) const {
+	return INVALID;
+      }
+      
+      /// \brief Running node of the iterator
+      ///
+      /// Returns the running node of the iterator
+      Node runningNode(IncEdgeIt) const {
+	return INVALID;
+      }
+
+      template <typename Graph>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<IterableUGraphComponent<>, Graph>();
+	  checkConcept<MappableUGraphComponent<>, Graph>();
+	}
+      };
+
+    };
+
+    /// @}
+
+  }
+
+}
+
+#endif
Index: lemon/dag_shortest_path.h
===================================================================
--- lemon/dag_shortest_path.h	(revision 2151)
+++ lemon/dag_shortest_path.h	(revision 2260)
@@ -94,5 +94,5 @@
     ///
     /// The type of the map that stores the edge lengths.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _LengthMap LengthMap;
 
@@ -112,5 +112,5 @@
     /// The type of the map that stores the last
     /// edges of the shortest paths.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename _Graph::Edge> PredMap;
@@ -129,5 +129,5 @@
     ///
     /// The type of the map that stores the dists of the nodes.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename _LengthMap::Value> 
@@ -206,5 +206,5 @@
     ///
     /// The type of the map that stores the edge lengths.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _LengthMap LengthMap;
 
@@ -224,5 +224,5 @@
     /// The type of the map that stores the last
     /// edges of the longest paths.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename _Graph::Edge> PredMap;
@@ -241,5 +241,5 @@
     ///
     /// The type of the map that stores the dists of the nodes.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename _LengthMap::Value> 
@@ -263,5 +263,5 @@
   /// This class provides an efficient implementation of a Dag sortest path
   /// searching algorithm. The edge lengths are passed to the algorithm
-  /// using a \ref concept::ReadMap "ReadMap", so it is easy to change it
+  /// using a \ref concepts::ReadMap "ReadMap", so it is easy to change it
   /// to any kind of length.
   ///
@@ -269,5 +269,5 @@
   ///
   /// The type of the length is determined by the
-  /// \ref concept::ReadMap::Value "Value" of the length map.
+  /// \ref concepts::ReadMap::Value "Value" of the length map.
   ///
   /// \param _Graph The graph type the algorithm runs on. The default value
@@ -275,5 +275,5 @@
   /// DagShortestPath, it is only passed to \ref DagShortestPathDefaultTraits.
   /// \param _LengthMap This read-only EdgeMap determines the lengths of the
-  /// edges. The default map type is \ref concept::Graph::EdgeMap 
+  /// edges. The default map type is \ref concepts::Graph::EdgeMap 
   /// "Graph::EdgeMap<int>".  The value of _LengthMap is not used directly 
   /// by DagShortestPath, it is only passed to \ref DagShortestPathDefaultTraits.  
@@ -812,5 +812,5 @@
     ///
     /// The type of the map that stores the edge lengths.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _LengthMap LengthMap;
 
@@ -830,5 +830,5 @@
     /// The type of the map that stores the last
     /// edges of the shortest paths.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     typedef NullMap <typename _Graph::Node,typename _Graph::Edge> PredMap;
 
@@ -842,5 +842,5 @@
     ///
     /// The type of the map that stores the dists of the nodes.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     typedef NullMap<typename Graph::Node, Value> DistMap;
     /// \brief Instantiates a DistMap.
Index: lemon/dfs.h
===================================================================
--- lemon/dfs.h	(revision 2156)
+++ lemon/dfs.h	(revision 2260)
@@ -49,5 +49,5 @@
     ///The type of the map that stores the last
     ///edges of the %DFS paths.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename GR::Edge> PredMap;
@@ -65,5 +65,5 @@
  
     ///The type of the map that indicates which nodes are processed.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///\todo named parameter to set this type, function to read and write.
     typedef NullMap<typename Graph::Node,bool> ProcessedMap;
@@ -84,5 +84,5 @@
  
     ///The type of the map that indicates which nodes are reached.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///\todo named parameter to set this type, function to read and write.
     typedef typename Graph::template NodeMap<bool> ReachedMap;
@@ -99,5 +99,5 @@
  
     ///The type of the map that stores the dists of the nodes.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<int> DistMap;
@@ -753,5 +753,5 @@
     ///The type of the map that stores the last
     ///edges of the %DFS paths.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef NullMap<typename Graph::Node,typename GR::Edge> PredMap;
@@ -773,5 +773,5 @@
  
     ///The type of the map that indicates which nodes are processed.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///\todo named parameter to set this type, function to read and write.
     typedef NullMap<typename Graph::Node,bool> ProcessedMap;
@@ -792,5 +792,5 @@
  
     ///The type of the map that indicates which nodes are reached.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///\todo named parameter to set this type, function to read and write.
     typedef typename Graph::template NodeMap<bool> ReachedMap;
@@ -807,5 +807,5 @@
  
     ///The type of the map that stores the dists of the nodes.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef NullMap<typename Graph::Node,int> DistMap;
@@ -1169,5 +1169,5 @@
     /// 
     /// The type of the map that indicates which nodes are reached.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     /// \todo named parameter to set this type, function to read and write.
     typedef typename Graph::template NodeMap<bool> ReachedMap;
Index: lemon/dijkstra.h
===================================================================
--- lemon/dijkstra.h	(revision 2230)
+++ lemon/dijkstra.h	(revision 2260)
@@ -49,5 +49,5 @@
 
     ///The type of the map that stores the edge lengths.
-    ///It must meet the \ref concept::ReadMap "ReadMap" concept.
+    ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef LM LengthMap;
     //The type of the length of the edges.
@@ -87,5 +87,5 @@
     ///The type of the map that stores the last
     ///edges of the shortest paths.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename GR::Edge> PredMap;
@@ -103,5 +103,5 @@
  
     ///The type of the map that stores whether a nodes is processed.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///By default it is a NullMap.
     ///\todo If it is set to a real map,
@@ -125,5 +125,5 @@
  
     ///The type of the map that stores the dists of the nodes.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename Graph::template NodeMap<typename LM::Value> DistMap;
@@ -143,9 +143,9 @@
   ///This class provides an efficient implementation of %Dijkstra algorithm.
   ///The edge lengths are passed to the algorithm using a
-  ///\ref concept::ReadMap "ReadMap",
+  ///\ref concepts::ReadMap "ReadMap",
   ///so it is easy to change it to any kind of length.
   ///
   ///The type of the length is determined by the
-  ///\ref concept::ReadMap::Value "Value" of the length map.
+  ///\ref concepts::ReadMap::Value "Value" of the length map.
   ///
   ///It is also possible to change the underlying priority heap.
@@ -158,5 +158,5 @@
   ///relatively time consuming process to compute the edge length if
   ///it is necessary. The default map type is \ref
-  ///concept::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
+  ///concepts::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
   ///of LM is not used directly by Dijkstra, it is only passed to \ref
   ///DijkstraDefaultTraits.  \param TR Traits class to set
@@ -820,5 +820,5 @@
 
     ///The type of the map that stores the edge lengths.
-    ///It must meet the \ref concept::ReadMap "ReadMap" concept.
+    ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef LM LengthMap;
     //The type of the length of the edges.
@@ -862,5 +862,5 @@
     ///The type of the map that stores the last
     ///edges of the shortest paths.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef NullMap <typename GR::Node,typename GR::Edge> PredMap;
@@ -881,5 +881,5 @@
  
     ///The type of the map that stores whether a nodes is processed.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///By default it is a NullMap.
     ///\todo If it is set to a real map,
@@ -903,5 +903,5 @@
  
     ///The type of the map that stores the dists of the nodes.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef NullMap<typename Graph::Node,typename LM::Value> DistMap;
Index: lemon/edge_set.h
===================================================================
--- lemon/edge_set.h	(revision 2224)
+++ lemon/edge_set.h	(revision 2260)
@@ -239,9 +239,9 @@
   ///
   /// \param _Graph The type of the graph which shares its node set with 
-  /// this class. Its interface must conform to the \ref concept::Graph
+  /// this class. Its interface must conform to the \ref concepts::Graph
   /// "Graph" concept.
   ///
   /// In the edge extension and removing it conforms to the 
-  /// \ref concept::Graph "Graph" concept.
+  /// \ref concepts::Graph "Graph" concept.
   template <typename _Graph>
   class ListEdgeSet : public EdgeSetExtender<ListEdgeSetBase<_Graph> > {
@@ -331,9 +331,9 @@
   ///
   /// \param _Graph The type of the graph which shares its node set with 
-  /// this class. Its interface must conform to the \ref concept::Graph
+  /// this class. Its interface must conform to the \ref concepts::Graph
   /// "Graph" concept.
   ///
   /// In the edge extension and removing it conforms to the 
-  /// \ref concept::UGraph "UGraph" concept.
+  /// \ref concepts::UGraph "UGraph" concept.
   template <typename _Graph>
   class ListUEdgeSet 
@@ -568,9 +568,9 @@
   ///
   /// \param _Graph The type of the graph which shares its node set with 
-  /// this class. Its interface must conform to the \ref concept::Graph
+  /// this class. Its interface must conform to the \ref concepts::Graph
   /// "Graph" concept.
   ///
   /// In the edge extension and removing it conforms to the 
-  /// \ref concept::Graph "Graph" concept.
+  /// \ref concepts::Graph "Graph" concept.
   template <typename _Graph>
   class SmartEdgeSet : public EdgeSetExtender<SmartEdgeSetBase<_Graph> > {
@@ -672,9 +672,9 @@
   ///
   /// \param _Graph The type of the graph which shares its node set with 
-  /// this class. Its interface must conform to the \ref concept::Graph
+  /// this class. Its interface must conform to the \ref concepts::Graph
   /// "Graph" concept.
   ///
   /// In the edge extension and removing it conforms to the 
-  /// \ref concept::UGraph "UGraph" concept.
+  /// \ref concepts::UGraph "UGraph" concept.
   template <typename _Graph>
   class SmartUEdgeSet 
Index: lemon/floyd_warshall.h
===================================================================
--- lemon/floyd_warshall.h	(revision 2184)
+++ lemon/floyd_warshall.h	(revision 2260)
@@ -95,5 +95,5 @@
     ///
     /// The type of the map that stores the edge lengths.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _LengthMap LengthMap;
 
@@ -130,5 +130,5 @@
     ///
     /// The type of the map that stores the dists of the nodes.
-    /// It must meet the \ref concept::WriteMatrixMap "WriteMatrixMap" concept.
+    /// It must meet the \ref concepts::WriteMatrixMap "WriteMatrixMap" concept.
     ///
     typedef DynamicMatrixMap<Graph, typename Graph::Node, Value> DistMap;
@@ -150,5 +150,5 @@
   /// This class provides an efficient implementation of \c Floyd-Warshall 
   /// algorithm. The edge lengths are passed to the algorithm using a
-  /// \ref concept::ReadMap "ReadMap", so it is easy to change it to any 
+  /// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any 
   /// kind of length.
   ///
@@ -163,5 +163,5 @@
   ///
   /// The type of the length is determined by the
-  /// \ref concept::ReadMap::Value "Value" of the length map.
+  /// \ref concepts::ReadMap::Value "Value" of the length map.
   ///
   /// \param _Graph The graph type the algorithm runs on. The default value
@@ -172,5 +172,5 @@
   /// relatively time consuming process to compute the edge length if
   /// it is necessary. The default map type is \ref
-  /// concept::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
+  /// concepts::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
   /// of _LengthMap is not used directly by FloydWarshall, it is only passed 
   /// to \ref FloydWarshallDefaultTraits.  \param _Traits Traits class to set
Index: lemon/fredman_tarjan.h
===================================================================
--- lemon/fredman_tarjan.h	(revision 2151)
+++ lemon/fredman_tarjan.h	(revision 2260)
@@ -37,5 +37,5 @@
 #include <lemon/graph_utils.h>
 
-#include <lemon/concept/ugraph.h>
+#include <lemon/concepts/ugraph.h>
 
 namespace lemon {
@@ -53,5 +53,5 @@
 
     ///The type of the map that stores the edge costs.
-    ///It must meet the \ref concept::ReadMap "ReadMap" concept.
+    ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef CM CostMap;
     //The type of the cost of the edges.
@@ -62,5 +62,5 @@
     ///The type of the map that stores whether an edge is in the
     ///spanning tree or not.
-    ///It must meet the \ref concept::ReadWriteMap "ReadWriteMap" concept.
+    ///It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
     ///By default it is a BoolEdgeMap.
     typedef typename UGraph::template UEdgeMap<bool> TreeMap;
@@ -89,9 +89,9 @@
   ///
   ///The edge costs are passed to the algorithm using a \ref
-  ///concept::ReadMap "ReadMap", so it is easy to change it to any
+  ///concepts::ReadMap "ReadMap", so it is easy to change it to any
   ///kind of cost.
   ///
   ///The type of the cost is determined by the \ref
-  ///concept::ReadMap::Value "Value" of the cost map.
+  ///concepts::ReadMap::Value "Value" of the cost map.
   ///
   ///\param GR The graph type the algorithm runs on. The default value
@@ -104,5 +104,5 @@
   ///relatively time consuming process to compute the edge cost if it
   ///is necessary. The default map type is \ref
-  ///concept::UGraph::UEdgeMap "UGraph::UEdgeMap<int>". The value of
+  ///concepts::UGraph::UEdgeMap "UGraph::UEdgeMap<int>". The value of
   ///CM is not used directly by FredmanTarjan, it is only passed to
   ///\ref FredmanTarjanDefaultTraits.
@@ -366,5 +366,5 @@
       _tree(0), local_tree(false)
     {
-      checkConcept<concept::UGraph, UGraph>();
+      checkConcept<concepts::UGraph, UGraph>();
     }
     
Index: lemon/full_graph.h
===================================================================
--- lemon/full_graph.h	(revision 2256)
+++ lemon/full_graph.h	(revision 2260)
@@ -168,9 +168,9 @@
   /// edges or nodes.
   /// Thus it conforms to
-  /// the \ref concept::Graph "Graph" concept and
+  /// the \ref concepts::Graph "Graph" concept and
   ///it also has an
   ///important extra feature that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
-  /// \sa concept::Graph.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
+  /// \sa concepts::Graph.
   ///
   /// \sa FullUGraph
@@ -385,5 +385,5 @@
   ///It also has an
   ///important extra feature that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
   ///
   /// \sa FullGraph
Index: lemon/graph_adaptor.h
===================================================================
--- lemon/graph_adaptor.h	(revision 2251)
+++ lemon/graph_adaptor.h	(revision 2260)
@@ -2493,5 +2493,5 @@
   ///
   /// This graph adaptor is fully conform to the 
-  /// \ref concept::Graph "Graph" concept and
+  /// \ref concepts::Graph "Graph" concept and
   /// contains some additional member functions and types. The 
   /// documentation of some member functions may be found just in the
Index: lemon/grid_ugraph.h
===================================================================
--- lemon/grid_ugraph.h	(revision 2256)
+++ lemon/grid_ugraph.h	(revision 2260)
@@ -293,8 +293,8 @@
   ///\endcode
   ///
-  /// The graph type is fully conform to the \ref concept::UGraph
+  /// The graph type is fully conform to the \ref concepts::UGraph
   /// "Undirected Graph" concept,  and it also has an
   ///important extra feature that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
   ///
   ///
Index: lemon/hypercube_graph.h
===================================================================
--- lemon/hypercube_graph.h	(revision 2242)
+++ lemon/hypercube_graph.h	(revision 2260)
@@ -190,6 +190,6 @@
   /// is 26. 
   ///
-  /// The graph type is fully conform to the \ref concept::Graph
-  /// concept but it does not conform to the \ref concept::UGraph.
+  /// The graph type is fully conform to the \ref concepts::Graph
+  /// concept but it does not conform to the \ref concepts::UGraph.
   ///
   /// \author Balazs Dezso
Index: lemon/johnson.h
===================================================================
--- lemon/johnson.h	(revision 2230)
+++ lemon/johnson.h	(revision 2260)
@@ -97,5 +97,5 @@
     ///
     /// The type of the map that stores the edge lengths.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _LengthMap LengthMap;
 
@@ -163,5 +163,5 @@
     ///
     /// The type of the matrix map that stores the dists of the nodes.
-    /// It must meet the \ref concept::WriteMatrixMap "WriteMatrixMap" concept.
+    /// It must meet the \ref concepts::WriteMatrixMap "WriteMatrixMap" concept.
     ///
     typedef DynamicMatrixMap<Graph, typename Graph::Node, Value> DistMap;
@@ -183,5 +183,5 @@
   /// This class provides an efficient implementation of \c %Johnson 
   /// algorithm. The edge lengths are passed to the algorithm using a
-  /// \ref concept::ReadMap "ReadMap", so it is easy to change it to any 
+  /// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any 
   /// kind of length.
   ///
@@ -198,5 +198,5 @@
   ///
   /// The type of the length is determined by the
-  /// \ref concept::ReadMap::Value "Value" of the length map.
+  /// \ref concepts::ReadMap::Value "Value" of the length map.
   ///
   /// \param _Graph The graph type the algorithm runs on. The default value
@@ -207,5 +207,5 @@
   /// relatively time consuming process to compute the edge length if
   /// it is necessary. The default map type is \ref
-  /// concept::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
+  /// concepts::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
   /// of _LengthMap is not used directly by Johnson, it is only passed 
   /// to \ref JohnsonDefaultTraits.  \param _Traits Traits class to set
Index: lemon/kruskal.h
===================================================================
--- lemon/kruskal.h	(revision 2259)
+++ lemon/kruskal.h	(revision 2260)
@@ -45,6 +45,6 @@
   ///
   /// \param g The graph the algorithm runs on.
-  /// It can be either \ref concept::Graph "directed" or 
-  /// \ref concept::UGraph "undirected".
+  /// It can be either \ref concepts::Graph "directed" or 
+  /// \ref concepts::UGraph "undirected".
   /// If the graph is directed, the algorithm consider it to be 
   /// undirected by disregarding the direction of the edges.
@@ -84,5 +84,5 @@
   ///
   /// \warning If kruskal runs on an
-  /// \ref lemon::concept::UGraph "undirected graph", be sure that the
+  /// \ref lemon::concepts::UGraph "undirected graph", be sure that the
   /// map storing the tree is also undirected
   /// (e.g. ListUGraph::UEdgeMap<bool>, otherwise the values of the
Index: lemon/lemon_reader.h
===================================================================
--- lemon/lemon_reader.h	(revision 2207)
+++ lemon/lemon_reader.h	(revision 2260)
@@ -42,5 +42,5 @@
 
 #include <lemon/concept_check.h>
-#include <lemon/concept/maps.h>
+#include <lemon/concepts/maps.h>
 
 namespace lemon {
@@ -832,5 +832,5 @@
     NodeSetReader& _readMap(std::string name, MapParameter map, 
 			    const Reader& reader = Reader()) {
-      checkConcept<concept::WriteMap<Node, typename Map::Value>, Map>();
+      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
       checkConcept<_reader_bits::ItemReader<typename Map::Value>, Reader>();
       if (readers.find(name) != readers.end()) {
@@ -1062,5 +1062,5 @@
     EdgeSetReader& _readMap(std::string name, MapParameter map, 
 			    const Reader& reader = Reader()) {
-      checkConcept<concept::WriteMap<Edge, typename Map::Value>, Map>();
+      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
       checkConcept<_reader_bits::ItemReader<typename Map::Value>, Reader>();
       if (readers.find(name) != readers.end()) {
@@ -1306,5 +1306,5 @@
     UEdgeSetReader& _readMap(std::string name, MapParameter map,
 				 const Reader& reader = Reader()) {
-      checkConcept<concept::WriteMap<UEdge, typename Map::Value>, Map>();
+      checkConcept<concepts::WriteMap<UEdge, typename Map::Value>, Map>();
       checkConcept<_reader_bits::ItemReader<typename Map::Value>, Reader>();
       if (readers.find(name) != readers.end()) {
@@ -1377,5 +1377,5 @@
 				    const Reader& reader = Reader()) { 
       checkConcept<_reader_bits::ItemReader<typename Map::Value>, Reader>();
-      checkConcept<concept::WriteMap<Edge, typename Map::Value>, Map>();
+      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
       readMap("+" + name, 
 	      _reader_bits::forwardComposeMap(graph, map), reader);
Index: lemon/lemon_writer.h
===================================================================
--- lemon/lemon_writer.h	(revision 2207)
+++ lemon/lemon_writer.h	(revision 2260)
@@ -41,5 +41,5 @@
 
 #include <lemon/concept_check.h>
-#include <lemon/concept/maps.h>
+#include <lemon/concepts/maps.h>
 
 
@@ -484,5 +484,5 @@
     NodeSetWriter& writeNodeMap(std::string name, const Map& map, 
 			    const Writer& writer = Writer()) {
-      checkConcept<concept::ReadMap<Node, typename Map::Value>, Map>();
+      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
       checkConcept<_writer_bits::ItemWriter<typename Map::Value>, Writer>();
       writers.push_back(
@@ -673,5 +673,5 @@
     EdgeSetWriter& writeEdgeMap(std::string name, const Map& map, 
 			    const Writer& writer = Writer()) {
-      checkConcept<concept::ReadMap<Edge, typename Map::Value>, Map>();
+      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
       checkConcept<_writer_bits::ItemWriter<typename Map::Value>, Writer>();
       writers.push_back(
@@ -879,5 +879,5 @@
     UEdgeSetWriter& writeUEdgeMap(std::string name, const Map& map, 
 					  const Writer& writer = Writer()) {
-      checkConcept<concept::ReadMap<UEdge, typename Map::Value>, Map>();
+      checkConcept<concepts::ReadMap<UEdge, typename Map::Value>, Map>();
       checkConcept<_writer_bits::ItemWriter<typename Map::Value>, Writer>();
       writers.push_back(
@@ -902,5 +902,5 @@
     UEdgeSetWriter& writeEdgeMap(std::string name, const Map& map, 
 				     const Writer& writer = Writer()) {
-      checkConcept<concept::ReadMap<Edge, typename Map::Value>, Map>();
+      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
       checkConcept<_writer_bits::ItemWriter<typename Map::Value>, Writer>();
       writeUEdge("+" + name, 
Index: lemon/list_graph.h
===================================================================
--- lemon/list_graph.h	(revision 2256)
+++ lemon/list_graph.h	(revision 2260)
@@ -319,5 +319,5 @@
   ///This is a simple and fast graph implementation.
   ///
-  ///It conforms to the \ref concept::Graph "Graph concept" and it
+  ///It conforms to the \ref concepts::Graph "Graph concept" and it
   ///also provides several additional useful extra functionalities.
   ///The most of the member functions and nested classes are
@@ -325,7 +325,7 @@
   ///
   ///An important extra feature of this graph implementation is that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
   ///
-  ///\sa concept::Graph.
+  ///\sa concepts::Graph.
 
   class ListGraph : public ExtendedListGraphBase {
@@ -749,10 +749,10 @@
   ///
   ///An important extra feature of this graph implementation is that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
   ///
   ///It conforms to the
-  ///\ref concept::UGraph "UGraph concept".
+  ///\ref concepts::UGraph "UGraph concept".
   ///
-  ///\sa concept::UGraph.
+  ///\sa concepts::UGraph.
   ///
   class ListUGraph : public ExtendedListUGraphBase {
@@ -1498,10 +1498,10 @@
   ///
   /// This is a bipartite undirected graph implementation.
-  /// It is conforms to the \ref concept::BpUGraph "BpUGraph concept".
+  /// It is conforms to the \ref concepts::BpUGraph "BpUGraph concept".
   ///
   ///An important extra feature of this graph implementation is that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
   ///
-  /// \sa concept::BpUGraph.
+  /// \sa concepts::BpUGraph.
   ///
   class ListBpUGraph : public ExtendedListBpUGraphBase {
Index: lemon/lp_base.h
===================================================================
--- lemon/lp_base.h	(revision 2218)
+++ lemon/lp_base.h	(revision 2260)
@@ -666,5 +666,5 @@
     ///std::map<AnyType,LpSolverBase::Col>
     ///\endcode
-    ///- an iterable lemon \ref concept::WriteMap "write map" like 
+    ///- an iterable lemon \ref concepts::WriteMap "write map" like 
     ///\code
     ///ListGraph::NodeMap<LpSolverBase::Col>
@@ -766,5 +766,5 @@
     ///std::map<AnyType,LpSolverBase::Row>
     ///\endcode
-    ///- an iterable lemon \ref concept::WriteMap "write map" like 
+    ///- an iterable lemon \ref concepts::WriteMap "write map" like 
     ///\code
     ///ListGraph::NodeMap<LpSolverBase::Row>
Index: lemon/maps.h
===================================================================
--- lemon/maps.h	(revision 2258)
+++ lemon/maps.h	(revision 2260)
@@ -30,5 +30,5 @@
 ///\brief Miscellaneous property maps
 ///
-///\todo This file has the same name as the concept file in concept/,
+///\todo This file has the same name as the concept file in concepts/,
 /// and this is not easily detectable in docs...
 
@@ -253,5 +253,5 @@
   ///Convert the \c Value of a map to another type.
 
-  ///This \ref concept::ReadMap "read only map"
+  ///This \ref concepts::ReadMap "read only map"
   ///converts the \c Value of a maps to type \c T.
   ///Its \c Key is inherited from \c M.
@@ -290,5 +290,5 @@
   ///Simple wrapping of the map
 
-  ///This \ref concept::ReadMap "read only map" returns the simple
+  ///This \ref concepts::ReadMap "read only map" returns the simple
   ///wrapping of the given map. Sometimes the reference maps cannot be
   ///combined with simple read maps. This map adaptor wraps the given
@@ -310,5 +310,5 @@
   ///Simple writeable wrapping of the map
 
-  ///This \ref concept::ReadMap "read only map" returns the simple
+  ///This \ref concepts::ReadMap "read only map" returns the simple
   ///wrapping of the given map. Sometimes the reference maps cannot be
   ///combined with simple read-write maps. This map adaptor wraps the
@@ -331,5 +331,5 @@
   ///Sum of two maps
 
-  ///This \ref concept::ReadMap "read only map" returns the sum of the two
+  ///This \ref concepts::ReadMap "read only map" returns the sum of the two
   ///given maps. Its \c Key and \c Value will be inherited from \c M1.
   ///The \c Key and \c Value of M2 must be convertible to those of \c M1.
@@ -364,5 +364,5 @@
   ///Shift a map with a constant.
 
-  ///This \ref concept::ReadMap "read only map" returns the sum of the
+  ///This \ref concepts::ReadMap "read only map" returns the sum of the
   ///given map and a constant value.
   ///Its \c Key and \c Value is inherited from \c M.
@@ -397,5 +397,5 @@
   ///Shift a map with a constant.
 
-  ///This \ref concept::ReadWriteMap "read-write map" returns the sum of the
+  ///This \ref concepts::ReadWriteMap "read-write map" returns the sum of the
   ///given map and a constant value. It makes also possible to write the map.
   ///Its \c Key and \c Value is inherited from \c M.
@@ -446,5 +446,5 @@
   ///Difference of two maps
 
-  ///This \ref concept::ReadMap "read only map" returns the difference
+  ///This \ref concepts::ReadMap "read only map" returns the difference
   ///of the values of the two
   ///given maps. Its \c Key and \c Value will be inherited from \c M1.
@@ -477,5 +477,5 @@
   ///Product of two maps
 
-  ///This \ref concept::ReadMap "read only map" returns the product of the
+  ///This \ref concepts::ReadMap "read only map" returns the product of the
   ///values of the two
   ///given
@@ -508,5 +508,5 @@
   ///Scales a maps with a constant.
 
-  ///This \ref concept::ReadMap "read only map" returns the value of the
+  ///This \ref concepts::ReadMap "read only map" returns the value of the
   ///given map multiplied from the left side with a constant value.
   ///Its \c Key and \c Value is inherited from \c M.
@@ -541,5 +541,5 @@
   ///Scales a maps with a constant.
 
-  ///This \ref concept::ReadWriteMap "read-write map" returns the value of the
+  ///This \ref concepts::ReadWriteMap "read-write map" returns the value of the
   ///given map multiplied from the left side with a constant value. It can
   ///be used as write map also if the given multiplier is not zero.
@@ -581,5 +581,5 @@
   ///Quotient of two maps
 
-  ///This \ref concept::ReadMap "read only map" returns the quotient of the
+  ///This \ref concepts::ReadMap "read only map" returns the quotient of the
   ///values of the two
   ///given maps. Its \c Key and \c Value will be inherited from \c M1.
@@ -611,5 +611,5 @@
   ///Composition of two maps
 
-  ///This \ref concept::ReadMap "read only map" returns the composition of
+  ///This \ref concepts::ReadMap "read only map" returns the composition of
   ///two
   ///given maps. That is to say, if \c m1 is of type \c M1 and \c m2 is
@@ -656,5 +656,5 @@
   ///
   ///
-  ///This \ref concept::ReadMap "read only map" takes two maps and a
+  ///This \ref concepts::ReadMap "read only map" takes two maps and a
   ///binary functor and returns the composition of
   ///the two
@@ -728,5 +728,5 @@
   ///Negative value of a map
 
-  ///This \ref concept::ReadMap "read only map" returns the negative
+  ///This \ref concepts::ReadMap "read only map" returns the negative
   ///value of the
   ///value returned by the
@@ -749,5 +749,5 @@
   ///Negative value of a map
 
-  ///This \ref concept::ReadWriteMap "read-write map" returns the negative
+  ///This \ref concepts::ReadWriteMap "read-write map" returns the negative
   ///value of the value returned by the
   ///given map. Its \c Key and \c Value will be inherited from \c M.
@@ -784,5 +784,5 @@
   ///Absolute value of a map
 
-  ///This \ref concept::ReadMap "read only map" returns the absolute value
+  ///This \ref concepts::ReadMap "read only map" returns the absolute value
   ///of the
   ///value returned by the
@@ -833,5 +833,5 @@
   ///Converts an STL style functor to a map
 
-  ///This \ref concept::ReadMap "read only map" returns the value
+  ///This \ref concepts::ReadMap "read only map" returns the value
   ///of a
   ///given map.
@@ -891,5 +891,5 @@
   ///
   ///For the sake of convenience it also works as
-  ///a ususal \ref concept::ReadMap "readable map",
+  ///a ususal \ref concepts::ReadMap "readable map",
   ///i.e. <tt>operator[]</tt> and the \c Key and \c Value typedefs also exist.
 
@@ -926,5 +926,5 @@
   ///Applies all map setting operations to two maps
 
-  ///This map has two \ref concept::ReadMap "readable map"
+  ///This map has two \ref concepts::ReadMap "readable map"
   ///parameters and each read request will be passed just to the
   ///first map. This class is the just readable map type of the ForkWriteMap.
@@ -950,7 +950,7 @@
   ///Applies all map setting operations to two maps
 
-  ///This map has two \ref concept::WriteMap "writable map"
+  ///This map has two \ref concepts::WriteMap "writable map"
   ///parameters and each write request will be passed to both of them.
-  ///If \c M1 is also \ref concept::ReadMap "readable",
+  ///If \c M1 is also \ref concepts::ReadMap "readable",
   ///then the read operations will return the
   ///corresponding values of \c M1.
@@ -997,5 +997,5 @@
   ///Logical 'not' of a map
   
-  ///This bool \ref concept::ReadMap "read only map" returns the 
+  ///This bool \ref concepts::ReadMap "read only map" returns the 
   ///logical negation of
   ///value returned by the
@@ -1018,5 +1018,5 @@
   ///Logical 'not' of a map with writing possibility
   
-  ///This bool \ref concept::ReadWriteMap "read-write map" returns the 
+  ///This bool \ref concepts::ReadWriteMap "read-write map" returns the 
   ///logical negation of value returned by the given map. When it is set,
   ///the opposite value is set to the original map.
Index: lemon/matrix_maps.h
===================================================================
--- lemon/matrix_maps.h	(revision 2088)
+++ lemon/matrix_maps.h	(revision 2260)
@@ -26,5 +26,5 @@
 #include <lemon/maps.h>
 
-#include <lemon/concept/matrix_maps.h>
+#include <lemon/concepts/matrix_maps.h>
 
 /// \file
@@ -32,5 +32,5 @@
 /// \brief Maps indexed with pairs of items.
 ///
-/// \todo This file has the same name as the concept file in concept/,
+/// \todo This file has the same name as the concept file in concepts/,
 ///  and this is not easily detectable in docs...
 namespace lemon {
@@ -296,5 +296,5 @@
     template <typename CMap>
     DynamicMatrixMap& operator=(const CMap& _cmap){
-      checkConcept<concept::ReadMatrixMap<FirstKey, SecondKey, Value>, CMap>();
+      checkConcept<concepts::ReadMatrixMap<FirstKey, SecondKey, Value>, CMap>();
       typename Parent::Notifier* notifier = Parent::getNotifier();
       Key first, second;
@@ -433,5 +433,5 @@
     template <typename CMap>
     DynamicSymMatrixMap& operator=(const CMap& _cmap){
-      checkConcept<concept::ReadMatrixMap<FirstKey, SecondKey, Value>, CMap>();
+      checkConcept<concepts::ReadMatrixMap<FirstKey, SecondKey, Value>, CMap>();
       typename Parent::Notifier* notifier = Parent::getNotifier();
       Key first, second;
@@ -520,5 +520,5 @@
   ///needed.
   ///
-  ///This map meet with the concept::ReferenceMatrixMap<typename K1,
+  ///This map meet with the concepts::ReferenceMatrixMap<typename K1,
   ///typename K2, typename V, typename R, typename CR> called as
   ///"ReferenceMatrixMap".
@@ -861,5 +861,5 @@
     template <typename CMap>
     DynamicAsymMatrixMap& operator=(const CMap& _cdmap){
-      checkConcept<concept::ReadMatrixMap<FirstKey, SecondKey, Value>, CMap>();
+      checkConcept<concepts::ReadMatrixMap<FirstKey, SecondKey, Value>, CMap>();
       const typename FirstKeyProxy::Notifier* notifierFirstKey = 
         _first_key_proxy.getNotifier();
Index: lemon/min_cost_arborescence.h
===================================================================
--- lemon/min_cost_arborescence.h	(revision 2259)
+++ lemon/min_cost_arborescence.h	(revision 2260)
@@ -46,5 +46,5 @@
     ///
     /// The type of the map that stores the edge costs.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _CostMap CostMap;
 
@@ -58,5 +58,5 @@
     ///
     /// The type of the map that stores which edges are in the arborescence.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     /// Initially it will be set to false on each edge. After it
     /// will set all arborescence edges once.
@@ -111,5 +111,5 @@
   /// relatively time consuming process to compute the edge cost if
   /// it is necessary. The default map type is \ref
-  /// concept::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
+  /// concepts::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
   /// of _CostMap is not used directly by MinCostArborescence, 
   /// it is only passed to \ref MinCostArborescenceDefaultTraits.  
Index: lemon/min_cut.h
===================================================================
--- lemon/min_cut.h	(revision 2225)
+++ lemon/min_cut.h	(revision 2260)
@@ -68,5 +68,5 @@
     ///
     /// The type of the map that stores the edge capacities.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _CapacityMap CapacityMap;
 
@@ -114,5 +114,5 @@
     ///
     /// The type of the map that stores whether a nodes is processed.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     /// By default it is a NullMap.
     typedef NullMap<typename Graph::Node, bool> ProcessedMap;
@@ -135,5 +135,5 @@
     /// 
     /// The type of the map that stores the cardinalities of the nodes.
-    /// It must meet the \ref concept::WriteMap "WriteMap" concept.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
     typedef typename Graph::template NodeMap<Value> CardinalityMap;
 
@@ -163,9 +163,9 @@
   ///
   /// The edge capacities are passed to the algorithm using a
-  /// \ref concept::ReadMap "ReadMap", so it is easy to change it to any 
+  /// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any 
   /// kind of capacity.
   ///
   /// The type of the capacity is determined by the \ref 
-  /// concept::ReadMap::Value "Value" of the capacity map.
+  /// concepts::ReadMap::Value "Value" of the capacity map.
   ///
   /// It is also possible to change the underlying priority heap.
@@ -180,5 +180,5 @@
   /// relatively time consuming process to compute the edge capacity if
   /// it is necessary. The default map type is \ref
-  /// concept::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
+  /// concepts::Graph::EdgeMap "Graph::EdgeMap<int>".  The value
   /// of CapacityMap is not used directly by search algorithm, it is only 
   /// passed to \ref MaxCardinalitySearchDefaultTraits.  
@@ -715,5 +715,5 @@
     ///
     /// The type of the map that stores the edge capacities.
-    /// It must meet the \ref concept::ReadMap "ReadMap" concept.
+    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef _CapacityMap CapacityMap;
 
Index: lemon/prim.h
===================================================================
--- lemon/prim.h	(revision 2230)
+++ lemon/prim.h	(revision 2260)
@@ -31,5 +31,5 @@
 #include <lemon/bits/traits.h>
 
-#include <lemon/concept/ugraph.h>
+#include <lemon/concepts/ugraph.h>
 
 namespace lemon {
@@ -47,5 +47,5 @@
 
     ///The type of the map that stores the edge costs.
-    ///It must meet the \ref concept::ReadMap "ReadMap" concept.
+    ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
     typedef CM CostMap;
     //The type of the cost of the edges.
@@ -83,5 +83,5 @@
     ///The type of the map that stores the last
     ///edges of the minimum spanning tree.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///
     typedef typename UGraph::template NodeMap<typename GR::UEdge> PredMap;
@@ -114,5 +114,5 @@
  
     ///The type of the map that stores whether a nodes is processed.
-    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
     ///By default it is a NodeMap<bool>.
     typedef NullMap<typename UGraph::Node,bool> ProcessedMap;
@@ -141,9 +141,9 @@
   ///
   ///The edge costs are passed to the algorithm using a
-  ///\ref concept::ReadMap "ReadMap",
+  ///\ref concepts::ReadMap "ReadMap",
   ///so it is easy to change it to any kind of cost.
   ///
   ///The type of the cost is determined by the
-  ///\ref concept::ReadMap::Value "Value" of the cost map.
+  ///\ref concepts::ReadMap::Value "Value" of the cost map.
   ///
   ///It is also possible to change the underlying priority heap.
@@ -157,5 +157,5 @@
   ///relatively time consuming process to compute the edge cost if
   ///it is necessary. The default map type is \ref
-  ///concept::UGraph::UEdgeMap "UGraph::UEdgeMap<int>".  The value
+  ///concepts::UGraph::UEdgeMap "UGraph::UEdgeMap<int>".  The value
   ///of CM is not used directly by Prim, it is only passed to \ref
   ///PrimDefaultTraits.
@@ -413,5 +413,5 @@
       _heap(NULL), local_heap(false)
     {
-      checkConcept<concept::UGraph, UGraph>();
+      checkConcept<concepts::UGraph, UGraph>();
     }
     
Index: lemon/smart_graph.h
===================================================================
--- lemon/smart_graph.h	(revision 2256)
+++ lemon/smart_graph.h	(revision 2260)
@@ -195,9 +195,9 @@
   ///node and edge deletions</b>.
   ///It conforms to 
-  ///the \ref concept::Graph "Graph concept" with an
+  ///the \ref concepts::Graph "Graph concept" with an
   ///important extra feature that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
-  ///
-  ///\sa concept::Graph.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
+  ///
+  ///\sa concepts::Graph.
   ///
   ///\author Alpar Juttner
@@ -381,11 +381,11 @@
   /// node and edge deletions</b>.
   /// Except from this it conforms to 
-  /// the \ref concept::UGraph "UGraph concept".
+  /// the \ref concepts::UGraph "UGraph concept".
   ///
   ///It also has an
   ///important extra feature that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
-  ///
-  /// \sa concept::UGraph.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
+  ///
+  /// \sa concepts::UGraph.
   ///
   /// \todo Snapshot hasn't been implemented yet.
@@ -763,11 +763,11 @@
   /// that <b> it does not support node and edge deletions</b>.
   /// Except from this it conforms to 
-  /// the \ref concept::BpUGraph "BpUGraph concept".
+  /// the \ref concepts::BpUGraph "BpUGraph concept".
   ///
   ///It also has an
   ///important extra feature that
-  ///its maps are real \ref concept::ReferenceMap "reference map"s.
-  ///
-  /// \sa concept::BpUGraph.
+  ///its maps are real \ref concepts::ReferenceMap "reference map"s.
+  ///
+  /// \sa concepts::BpUGraph.
   ///
   class SmartBpUGraph : public ExtendedSmartBpUGraphBase {
Index: lemon/topology.h
===================================================================
--- lemon/topology.h	(revision 2111)
+++ lemon/topology.h	(revision 2260)
@@ -26,6 +26,6 @@
 #include <lemon/maps.h>
 
-#include <lemon/concept/graph.h>
-#include <lemon/concept/ugraph.h>
+#include <lemon/concepts/graph.h>
+#include <lemon/concepts/ugraph.h>
 #include <lemon/concept_check.h>
 
@@ -54,5 +54,5 @@
   template <typename UGraph>
   bool connected(const UGraph& graph) {
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::NodeIt NodeIt;
     if (NodeIt(graph) == INVALID) return true;
@@ -79,5 +79,5 @@
   template <typename UGraph>
   int countConnectedComponents(const UGraph &graph) {
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::Node Node;
     typedef typename UGraph::Edge Edge;
@@ -127,8 +127,8 @@
   template <class UGraph, class NodeMap>
   int connectedComponents(const UGraph &graph, NodeMap &compMap) {
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::Node Node;
     typedef typename UGraph::Edge Edge;
-    checkConcept<concept::WriteMap<Node, int>, NodeMap>();
+    checkConcept<concepts::WriteMap<Node, int>, NodeMap>();
 
     typedef NullMap<Node, Edge> PredMap;
@@ -245,5 +245,5 @@
   template <typename Graph>
   bool stronglyConnected(const Graph& graph) {
-    checkConcept<concept::Graph, Graph>();
+    checkConcept<concepts::Graph, Graph>();
 
     typedef typename Graph::Node Node;
@@ -303,5 +303,5 @@
   template <typename Graph>
   int countStronglyConnectedComponents(const Graph& graph) {
-    checkConcept<concept::Graph, Graph>();
+    checkConcept<concepts::Graph, Graph>();
 
     using namespace _topology_bits;
@@ -372,8 +372,8 @@
   template <typename Graph, typename NodeMap>
   int stronglyConnectedComponents(const Graph& graph, NodeMap& compMap) {
-    checkConcept<concept::Graph, Graph>();
+    checkConcept<concepts::Graph, Graph>();
     typedef typename Graph::Node Node;
     typedef typename Graph::NodeIt NodeIt;
-    checkConcept<concept::WriteMap<Node, int>, NodeMap>();
+    checkConcept<concepts::WriteMap<Node, int>, NodeMap>();
 
     using namespace _topology_bits;
@@ -435,9 +435,9 @@
   template <typename Graph, typename EdgeMap>
   int stronglyConnectedCutEdges(const Graph& graph, EdgeMap& cutMap) {
-    checkConcept<concept::Graph, Graph>();
+    checkConcept<concepts::Graph, Graph>();
     typedef typename Graph::Node Node;
     typedef typename Graph::Edge Edge;
     typedef typename Graph::NodeIt NodeIt;
-    checkConcept<concept::WriteMap<Edge, bool>, EdgeMap>();
+    checkConcept<concepts::WriteMap<Edge, bool>, EdgeMap>();
 
     using namespace _topology_bits;
@@ -731,5 +731,5 @@
   template <typename UGraph>
   int countBiNodeConnectedComponents(const UGraph& graph) {
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::NodeIt NodeIt;
 
@@ -775,8 +775,8 @@
   int biNodeConnectedComponents(const UGraph& graph, 
 				UEdgeMap& compMap) {
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::NodeIt NodeIt;
     typedef typename UGraph::UEdge UEdge;
-    checkConcept<concept::WriteMap<UEdge, int>, UEdgeMap>();
+    checkConcept<concepts::WriteMap<UEdge, int>, UEdgeMap>();
 
     using namespace _topology_bits;
@@ -815,8 +815,8 @@
   template <typename UGraph, typename NodeMap>
   int biNodeConnectedCutNodes(const UGraph& graph, NodeMap& cutMap) {
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::Node Node;
     typedef typename UGraph::NodeIt NodeIt;
-    checkConcept<concept::WriteMap<Node, bool>, NodeMap>();
+    checkConcept<concepts::WriteMap<Node, bool>, NodeMap>();
 
     using namespace _topology_bits;
@@ -1058,5 +1058,5 @@
   template <typename UGraph>
   int countBiEdgeConnectedComponents(const UGraph& graph) { 
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::NodeIt NodeIt;
 
@@ -1101,8 +1101,8 @@
   template <typename UGraph, typename NodeMap>
   int biEdgeConnectedComponents(const UGraph& graph, NodeMap& compMap) { 
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::NodeIt NodeIt;
     typedef typename UGraph::Node Node;
-    checkConcept<concept::WriteMap<Node, int>, NodeMap>();
+    checkConcept<concepts::WriteMap<Node, int>, NodeMap>();
 
     using namespace _topology_bits;
@@ -1142,8 +1142,8 @@
   template <typename UGraph, typename UEdgeMap>
   int biEdgeConnectedCutEdges(const UGraph& graph, UEdgeMap& cutMap) { 
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::NodeIt NodeIt;
     typedef typename UGraph::UEdge UEdge;
-    checkConcept<concept::WriteMap<UEdge, bool>, UEdgeMap>();
+    checkConcept<concepts::WriteMap<UEdge, bool>, UEdgeMap>();
 
     using namespace _topology_bits;
@@ -1206,6 +1206,6 @@
     using namespace _topology_bits;
 
-    checkConcept<concept::Graph, Graph>();
-    checkConcept<concept::WriteMap<typename Graph::Node, int>, NodeMap>();
+    checkConcept<concepts::Graph, Graph>();
+    checkConcept<concepts::WriteMap<typename Graph::Node, int>, NodeMap>();
 
     typedef typename Graph::Node Node;
@@ -1248,6 +1248,6 @@
     using namespace _topology_bits;
 
-    checkConcept<concept::Graph, Graph>();
-    checkConcept<concept::ReadWriteMap<typename Graph::Node, int>, NodeMap>();
+    checkConcept<concepts::Graph, Graph>();
+    checkConcept<concepts::ReadWriteMap<typename Graph::Node, int>, NodeMap>();
 
     typedef typename Graph::Node Node;
@@ -1291,5 +1291,5 @@
   bool dag(const Graph& graph) {
 
-    checkConcept<concept::Graph, Graph>();
+    checkConcept<concepts::Graph, Graph>();
 
     typedef typename Graph::Node Node;
@@ -1332,5 +1332,5 @@
   template <typename UGraph>
   bool acyclic(const UGraph& graph) {
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::Node Node;
     typedef typename UGraph::NodeIt NodeIt;
@@ -1365,5 +1365,5 @@
   template <typename UGraph>
   bool tree(const UGraph& graph) {
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     typedef typename UGraph::Node Node;
     typedef typename UGraph::NodeIt NodeIt;
@@ -1403,5 +1403,5 @@
   template<typename UGraph>
   inline bool bipartite(const UGraph &graph){
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     
     typedef typename UGraph::NodeIt NodeIt;
@@ -1440,5 +1440,5 @@
   template<typename UGraph, typename NodeMap>
   inline bool bipartitePartitions(const UGraph &graph, NodeMap &partMap){
-    checkConcept<concept::UGraph, UGraph>();
+    checkConcept<concepts::UGraph, UGraph>();
     
     typedef typename UGraph::Node Node;
Index: lemon/vmap.h
===================================================================
--- lemon/vmap.h	(revision 1978)
+++ lemon/vmap.h	(revision 2260)
@@ -60,5 +60,5 @@
   };
   
-  ///Makes a virtual map from a \ref concept::ReadMap "ReadMap"
+  ///Makes a virtual map from a \ref concepts::ReadMap "ReadMap"
   template<class M, class K=typename M::Key,class V=typename M::Value>
   class VReadMap : public VMapBase<K,V> 
@@ -75,5 +75,5 @@
   vReadMap(const M& m) {return VReadMap<M,K,V>(m);}
 
-  ///Makes a virtual map from a \ref concept::WriteMap "WriteMap"
+  ///Makes a virtual map from a \ref concepts::WriteMap "WriteMap"
   template<class M, class K=typename M::Key,class V=typename M::Value>
   class VWriteMap :public VMapBase<K,V> 
@@ -90,5 +90,5 @@
   vWriteMap(const M& m) {return VReadMap<M,K,V>(m);}
 
-  ///Makes a virtual map from a \ref concept::ReadWriteMap "ReadWriteMap"
+  ///Makes a virtual map from a \ref concepts::ReadWriteMap "ReadWriteMap"
   template<class M, class K=typename M::Key,class V=typename M::Value>
   class VReadWriteMap :public VMapBase<K,V>
