Index: src/hugo/graph_wrapper.h
===================================================================
--- src/hugo/graph_wrapper.h	(revision 626)
+++ src/hugo/graph_wrapper.h	(revision 650)
@@ -12,4 +12,5 @@
 
 #include <hugo/invalid.h>
+#include <hugo/maps.h>
 //#include <iter_map.h>
 
@@ -104,4 +105,8 @@
       Node() { }
       Node(const typename Graph::Node& _n) : Graph::Node(_n) { }
+      // /// \bug construction throughrthr multiple levels should be 
+      // /// handled better
+      // Node(const typename ParentGraph::ParentGraph::Node& _n) : 
+      // Graph::Node(_n) { }
       Node(const Invalid& i) : Graph::Node(i) { }
     };
@@ -203,4 +208,9 @@
     void clear() const { graph->clear(); }
     
+    bool forward(const Edge& e) const { graph->forward(e); }
+    bool backward(const Edge& e) const { graph->backward(e); }
+    
+    Edge opposite(const Edge& e) const { Edge(graph->opposite(e)); }
+
     template<typename T> class NodeMap : public Graph::template NodeMap<T> { 
       typedef typename Graph::template NodeMap<T> Parent;
@@ -228,4 +238,6 @@
   template<typename Graph>
   class RevGraphWrapper : public GraphWrapper<Graph> {
+  public:
+    typedef GraphWrapper<Graph> Parent; 
   protected:
     RevGraphWrapper() : GraphWrapper<Graph>() { }
@@ -308,4 +320,6 @@
 	   typename EdgeFilterMap>
   class SubGraphWrapper : public GraphWrapper<Graph> {
+  public:
+    typedef GraphWrapper<Graph> Parent;
   protected:
     NodeFilterMap* node_filter_map;
@@ -322,5 +336,4 @@
     
   public:
-
     SubGraphWrapper(Graph& _graph, NodeFilterMap& _node_filter_map, 
 		    EdgeFilterMap& _edge_filter_map) : 
@@ -497,4 +510,6 @@
   template<typename Graph>
   class UndirGraphWrapper : public GraphWrapper<Graph> {
+  public:
+    typedef GraphWrapper<Graph> Parent; 
   protected:
     UndirGraphWrapper() : GraphWrapper<Graph>() { }
@@ -592,32 +607,42 @@
 
 
-  ///\brief A wrapper for composing bidirected graph from a directed one. 
+
+  ///\brief A wrapper for composing a subgraph of a 
+  /// bidirected graph composed from a directed one. 
   /// experimental, for fezso's sake.
   ///
-  /// A wrapper for composing bidirected graph from a directed one. 
+  /// A wrapper for composing a subgraps of a 
+  /// bidirected graph composed from a directed one. 
   /// experimental, for fezso's sake.
   /// A bidirected graph is composed over the directed one without physical 
   /// storage. As the oppositely directed edges are logically different ones 
   /// the maps are able to attach different values for them.
-  template<typename Graph>
-  class BidirGraphWrapper : public GraphWrapper<Graph> {
+  template<typename Graph, 
+	   typename ForwardFilterMap, typename BackwardFilterMap>
+  class SubBidirGraphWrapper : public GraphWrapper<Graph> {
+  public:
+    typedef GraphWrapper<Graph> Parent; 
   protected:
     //const CapacityMap* capacity;
     //FlowMap* flow;
 
-    BidirGraphWrapper() : GraphWrapper<Graph>()/*, 
+    ForwardFilterMap* forward_filter;
+    BackwardFilterMap* backward_filter;
+
+    SubBidirGraphWrapper() : GraphWrapper<Graph>()/*, 
 						 capacity(0), flow(0)*/ { }
-//     void setCapacityMap(const CapacityMap& _capacity) {
-//       capacity=&_capacity;
-//     }
-//     void setFlowMap(FlowMap& _flow) {
-//       flow=&_flow;
-//     }
-
-  public:
-
-    BidirGraphWrapper(Graph& _graph/*, const CapacityMap& _capacity, 
-				     FlowMap& _flow*/) : 
-      GraphWrapper<Graph>(_graph)/*, capacity(&_capacity), flow(&_flow)*/ { }
+    void setForwardFilterMap(ForwardFilterMap& _forward_filter) {
+      forward_filter=&_forward_filter;
+    }
+    void setBackwardFilterMap(BackwardFilterMap& _backward_filter) {
+      backward_filter=&_backward_filter;
+    }
+
+  public:
+
+    SubBidirGraphWrapper(Graph& _graph, ForwardFilterMap& _forward_filter, 
+			 BackwardFilterMap& _backward_filter) : 
+      GraphWrapper<Graph>(_graph), 
+      forward_filter(&_forward_filter), backward_filter(&_backward_filter) { }
 
     class Edge; 
@@ -633,5 +658,6 @@
 
     class Edge : public Graph::Edge {
-      friend class BidirGraphWrapper<Graph>;
+      friend class SubBidirGraphWrapper<Graph, 
+					ForwardFilterMap, BackwardFilterMap>;
       ///\bug ez nem is kell
       //template<typename T> friend class NodeMap;
@@ -660,5 +686,6 @@
 
     class OutEdgeIt {
-      friend class BidirGraphWrapper<Graph>;
+      friend class SubBidirGraphWrapper<Graph, 
+					ForwardFilterMap, BackwardFilterMap>;
     protected:
       typename Graph::OutEdgeIt out;
@@ -671,12 +698,13 @@
       OutEdgeIt(const Invalid& i) : out(i), in(i), backward(true) { }
 //the unique invalid iterator
-      OutEdgeIt(const BidirGraphWrapper<Graph>& _G, Node v) { 
+      OutEdgeIt(const SubBidirGraphWrapper<Graph, 
+		ForwardFilterMap, BackwardFilterMap>& _G, Node v) { 
 	backward=false;
 	_G.graph->first(out, v);
-	while(_G.graph->valid(out) && !_G.enabled(*this)) { _G.graph->next(out); }
+	while(_G.graph->valid(out) && !(*_G.forward_filter)[*this]) { _G.graph->next(out); }
 	if (!_G.graph->valid(out)) {
 	  backward=true;
 	  _G.graph->first(in, v);
-	  while(_G.graph->valid(in) && !_G.enabled(*this)) { _G.graph->next(in); }
+	  while(_G.graph->valid(in) && !(*_G.backward_filter)[*this]) { _G.graph->next(in); }
 	}
       }
@@ -694,5 +722,6 @@
 
     class InEdgeIt {
-      friend class BidirGraphWrapper<Graph>;
+      friend class SubBidirGraphWrapper<Graph, 
+					ForwardFilterMap, BackwardFilterMap>;
     protected:
       typename Graph::OutEdgeIt out;
@@ -705,12 +734,13 @@
       InEdgeIt(const Invalid& i) : out(i), in(i), backward(true) { }
 //the unique invalid iterator
-      InEdgeIt(const BidirGraphWrapper<Graph>& _G, Node v) { 
+      InEdgeIt(const SubBidirGraphWrapper<Graph, 
+	       ForwardFilterMap, BackwardFilterMap>& _G, Node v) { 
 	backward=false;
 	_G.graph->first(in, v);
-	while(_G.graph->valid(in) && !_G.enabled(*this)) { _G.graph->next(in); }
+	while(_G.graph->valid(in) && !(*_G.forward_filter)[*this]) { _G.graph->next(in); }
 	if (!_G.graph->valid(in)) {
 	  backward=true;
 	  _G.graph->first(out, v);
-	  while(_G.graph->valid(out) && !_G.enabled(*this)) { _G.graph->next(out); }
+	  while(_G.graph->valid(out) && !(*_G.backward_filter)[*this]) { _G.graph->next(out); }
 	}
       }
@@ -728,5 +758,6 @@
 
     class EdgeIt {
-      friend class BidirGraphWrapper<Graph>;
+      friend class SubBidirGraphWrapper<Graph, 
+					ForwardFilterMap, BackwardFilterMap>;
     protected:
       typename Graph::EdgeIt e;
@@ -735,12 +766,13 @@
       EdgeIt() { }
       EdgeIt(const Invalid& i) : e(i), backward(true) { }
-      EdgeIt(const BidirGraphWrapper<Graph>& _G) { 
+      EdgeIt(const SubBidirGraphWrapper<Graph, 
+	     ForwardFilterMap, BackwardFilterMap>& _G) { 
 	backward=false;
 	_G.graph->first(e);
-	while (_G.graph->valid(e) && !_G.enabled(*this)) _G.graph->next(e);
+	while (_G.graph->valid(e) && !(*_G.forward_filter)[*this]) _G.graph->next(e);
 	if (!_G.graph->valid(e)) {
 	  backward=true;
 	  _G.graph->first(e);
-	  while (_G.graph->valid(e) && !_G.enabled(*this)) _G.graph->next(e);
+	  while (_G.graph->valid(e) && !(*_G.backward_filter)[*this]) _G.graph->next(e);
 	}
       }
@@ -771,15 +803,15 @@
 	Node v=this->graph->aNode(e.out);
 	this->graph->next(e.out);
-	while(this->graph->valid(e.out) && !enabled(e)) { 
+	while(this->graph->valid(e.out) && !(*forward_filter)[e]) { 
 	  this->graph->next(e.out); }
 	if (!this->graph->valid(e.out)) {
 	  e.backward=true;
 	  this->graph->first(e.in, v); 
-	  while(this->graph->valid(e.in) && !enabled(e)) { 
+	  while(this->graph->valid(e.in) && !(*backward_filter)[e]) { 
 	    this->graph->next(e.in); }
 	}
       } else {
 	this->graph->next(e.in);
-	while(this->graph->valid(e.in) && !enabled(e)) { 
+	while(this->graph->valid(e.in) && !(*backward_filter)[e]) { 
 	  this->graph->next(e.in); } 
       }
@@ -791,15 +823,15 @@
 	Node v=this->graph->aNode(e.in);
 	this->graph->next(e.in);
-	while(this->graph->valid(e.in) && !enabled(e)) { 
+	while(this->graph->valid(e.in) && !(*forward_filter)[e]) { 
 	  this->graph->next(e.in); }
 	if (!this->graph->valid(e.in)) {
 	  e.backward=true;
 	  this->graph->first(e.out, v); 
-	  while(this->graph->valid(e.out) && !enabled(e)) { 
+	  while(this->graph->valid(e.out) && !(*backward_filter)[e]) { 
 	    this->graph->next(e.out); }
 	}
       } else {
 	this->graph->next(e.out);
-	while(this->graph->valid(e.out) && !enabled(e)) { 
+	while(this->graph->valid(e.out) && !(*backward_filter)[e]) { 
 	  this->graph->next(e.out); } 
       }
@@ -809,15 +841,15 @@
       if (!e.backward) {
 	this->graph->next(e.e);
-	while(this->graph->valid(e.e) && !enabled(e)) { 
+	while(this->graph->valid(e.e) && !(*forward_filter)[e]) { 
 	  this->graph->next(e.e); }
 	if (!this->graph->valid(e.e)) {
 	  e.backward=true;
 	  this->graph->first(e.e); 
-	  while(this->graph->valid(e.e) && !enabled(e)) { 
+	  while(this->graph->valid(e.e) && !(*backward_filter)[e]) { 
 	    this->graph->next(e.e); }
 	}
       } else {
 	this->graph->next(e.e);
-	while(this->graph->valid(e.e) && !enabled(e)) { 
+	while(this->graph->valid(e.e) && !(*backward_filter)[e]) { 
 	  this->graph->next(e.e); } 
       }
@@ -877,14 +909,14 @@
 //     }
 
-    bool enabled(const Edge& e) const { 
-      if (!e.backward) 
-//	return (capacity->get(e.out)-flow->get(e.out)); 
-	//return ((*capacity)[e]-(*flow)[e]);
-	return true;
-      else 
-//	return (flow->get(e.in)); 
-	//return ((*flow)[e]); 
-	return true;
-    }
+//     bool enabled(const Edge& e) const { 
+//       if (!e.backward) 
+// //	return (capacity->get(e.out)-flow->get(e.out)); 
+// 	//return ((*capacity)[e]-(*flow)[e]);
+// 	return true;
+//       else 
+// //	return (flow->get(e.in)); 
+// 	//return ((*flow)[e]); 
+// 	return true;
+//     }
 
 //     Number enabled(typename Graph::OutEdgeIt out) const { 
@@ -904,6 +936,10 @@
       typedef T ValueType;
       typedef Edge KeyType;
-      EdgeMap(const BidirGraphWrapper<Graph>& _G) : forward_map(*(_G.graph)), backward_map(*(_G.graph)) { }
-      EdgeMap(const BidirGraphWrapper<Graph>& _G, T a) : forward_map(*(_G.graph), a), backward_map(*(_G.graph), a) { }
+      EdgeMap(const SubBidirGraphWrapper<Graph, 
+	      ForwardFilterMap, BackwardFilterMap>& _G) : 
+	forward_map(*(_G.graph)), backward_map(*(_G.graph)) { }
+      EdgeMap(const SubBidirGraphWrapper<Graph, 
+	      ForwardFilterMap, BackwardFilterMap>& _G, T a) : 
+	forward_map(*(_G.graph), a), backward_map(*(_G.graph), a) { }
       void set(Edge e, T a) { 
 	if (!e.backward) 
@@ -930,4 +966,391 @@
     };
   };
+
+
+
+  ///\brief A wrapper for composing bidirected graph from a directed one. 
+  /// experimental, for fezso's sake.
+  ///
+  /// A wrapper for composing bidirected graph from a directed one. 
+  /// experimental, for fezso's sake.
+  /// A bidirected graph is composed over the directed one without physical 
+  /// storage. As the oppositely directed edges are logically different ones 
+  /// the maps are able to attach different values for them.
+  template<typename Graph>
+  class BidirGraphWrapper : 
+    public SubBidirGraphWrapper<
+    Graph, 
+    ConstMap<typename Graph::Edge, bool>, 
+    ConstMap<typename Graph::Edge, bool> > {
+  public:
+    typedef  SubBidirGraphWrapper<
+      Graph, 
+      ConstMap<typename Graph::Edge, bool>, 
+      ConstMap<typename Graph::Edge, bool> > Parent; 
+  protected:
+    ConstMap<typename Graph::Edge, bool> cm;
+    //const CapacityMap* capacity;
+    //FlowMap* flow;
+
+    BidirGraphWrapper() : Parent(), cm(true) { }
+//     void setCapacityMap(const CapacityMap& _capacity) {
+//       capacity=&_capacity;
+//     }
+//     void setFlowMap(FlowMap& _flow) {
+//       flow=&_flow;
+//     }
+
+  public:
+
+    BidirGraphWrapper(Graph& _graph) : Parent() { 
+      Parent::setGraph(_graph);
+      Parent::setForwardFilterMap(cm);
+      Parent::setBackwardFilterMap(cm);
+    }
+  };
+
+
+
+
+//   ///\brief A wrapper for composing bidirected graph from a directed one. 
+//   /// experimental, for fezso's sake.
+//   ///
+//   /// A wrapper for composing bidirected graph from a directed one. 
+//   /// experimental, for fezso's sake.
+//   /// A bidirected graph is composed over the directed one without physical 
+//   /// storage. As the oppositely directed edges are logically different ones 
+//   /// the maps are able to attach different values for them.
+//   template<typename Graph>
+//   class BidirGraphWrapper : public GraphWrapper<Graph> {
+//   public:
+//     typedef GraphWrapper<Graph> Parent; 
+//   protected:
+//     //const CapacityMap* capacity;
+//     //FlowMap* flow;
+
+//     BidirGraphWrapper() : GraphWrapper<Graph>()/*, 
+// 						 capacity(0), flow(0)*/ { }
+// //     void setCapacityMap(const CapacityMap& _capacity) {
+// //       capacity=&_capacity;
+// //     }
+// //     void setFlowMap(FlowMap& _flow) {
+// //       flow=&_flow;
+// //     }
+
+//   public:
+
+//     BidirGraphWrapper(Graph& _graph/*, const CapacityMap& _capacity, 
+// 				     FlowMap& _flow*/) : 
+//       GraphWrapper<Graph>(_graph)/*, capacity(&_capacity), flow(&_flow)*/ { }
+
+//     class Edge; 
+//     class OutEdgeIt; 
+//     friend class Edge; 
+//     friend class OutEdgeIt; 
+
+//     //template<typename T> class NodeMap;    
+//     template<typename T> class EdgeMap;
+
+//     typedef typename GraphWrapper<Graph>::Node Node;
+//     typedef typename GraphWrapper<Graph>::NodeIt NodeIt;
+
+//     class Edge : public Graph::Edge {
+//       friend class BidirGraphWrapper<Graph>;
+//       ///\bug ez nem is kell
+//       //template<typename T> friend class NodeMap;
+//       template<typename T> friend class EdgeMap;
+//     protected:
+//       bool backward; //true, iff backward
+// //      typename Graph::Edge e;
+//     public:
+//       Edge() { }
+//       ///\bug =false kell-e? zsoltnak kell az addEdge miatt
+//       Edge(const typename Graph::Edge& _e, bool _backward=false) : 
+// 	Graph::Edge(_e), backward(_backward) { }
+//       Edge(const Invalid& i) : Graph::Edge(i), backward(true) { }
+// //the unique invalid iterator
+//       friend bool operator==(const Edge& u, const Edge& v) { 
+// 	return (v.backward==u.backward && 
+// 		static_cast<typename Graph::Edge>(u)==
+// 		static_cast<typename Graph::Edge>(v));
+//       } 
+//       friend bool operator!=(const Edge& u, const Edge& v) { 
+// 	return (v.backward!=u.backward || 
+// 		static_cast<typename Graph::Edge>(u)!=
+// 		static_cast<typename Graph::Edge>(v));
+//       } 
+//     };
+
+//     class OutEdgeIt {
+//       friend class BidirGraphWrapper<Graph>;
+//     protected:
+//       typename Graph::OutEdgeIt out;
+//       typename Graph::InEdgeIt in;
+//       bool backward;
+//     public:
+//       OutEdgeIt() { }
+//       //FIXME
+// //      OutEdgeIt(const Edge& e) : Edge(e) { }
+//       OutEdgeIt(const Invalid& i) : out(i), in(i), backward(true) { }
+// //the unique invalid iterator
+//       OutEdgeIt(const BidirGraphWrapper<Graph>& _G, Node v) { 
+// 	backward=false;
+// 	_G.graph->first(out, v);
+// 	while(_G.graph->valid(out) && !_G.enabled(*this)) { _G.graph->next(out); }
+// 	if (!_G.graph->valid(out)) {
+// 	  backward=true;
+// 	  _G.graph->first(in, v);
+// 	  while(_G.graph->valid(in) && !_G.enabled(*this)) { _G.graph->next(in); }
+// 	}
+//       }
+//       operator Edge() const { 
+// //	Edge e;
+// //	e.forward=this->forward;
+// //	if (this->forward) e=out; else e=in;
+// //	return e;
+// 	if (this->backward) 
+// 	  return Edge(in, this->backward); 
+// 	else 
+// 	  return Edge(out, this->backward);
+//       }
+//     };
+
+//     class InEdgeIt {
+//       friend class BidirGraphWrapper<Graph>;
+//     protected:
+//       typename Graph::OutEdgeIt out;
+//       typename Graph::InEdgeIt in;
+//       bool backward;
+//     public:
+//       InEdgeIt() { }
+//       //FIXME
+// //      OutEdgeIt(const Edge& e) : Edge(e) { }
+//       InEdgeIt(const Invalid& i) : out(i), in(i), backward(true) { }
+// //the unique invalid iterator
+//       InEdgeIt(const BidirGraphWrapper<Graph>& _G, Node v) { 
+// 	backward=false;
+// 	_G.graph->first(in, v);
+// 	while(_G.graph->valid(in) && !_G.enabled(*this)) { _G.graph->next(in); }
+// 	if (!_G.graph->valid(in)) {
+// 	  backward=true;
+// 	  _G.graph->first(out, v);
+// 	  while(_G.graph->valid(out) && !_G.enabled(*this)) { _G.graph->next(out); }
+// 	}
+//       }
+//       operator Edge() const { 
+// //	Edge e;
+// //	e.forward=this->forward;
+// //	if (this->forward) e=out; else e=in;
+// //	return e;
+// 	if (this->backward) 
+// 	  return Edge(out, this->backward); 
+// 	else 
+// 	  return Edge(in, this->backward);
+//       }
+//     };
+
+//     class EdgeIt {
+//       friend class BidirGraphWrapper<Graph>;
+//     protected:
+//       typename Graph::EdgeIt e;
+//       bool backward;
+//     public:
+//       EdgeIt() { }
+//       EdgeIt(const Invalid& i) : e(i), backward(true) { }
+//       EdgeIt(const BidirGraphWrapper<Graph>& _G) { 
+// 	backward=false;
+// 	_G.graph->first(e);
+// 	while (_G.graph->valid(e) && !_G.enabled(*this)) _G.graph->next(e);
+// 	if (!_G.graph->valid(e)) {
+// 	  backward=true;
+// 	  _G.graph->first(e);
+// 	  while (_G.graph->valid(e) && !_G.enabled(*this)) _G.graph->next(e);
+// 	}
+//       }
+//       operator Edge() const { 
+// 	return Edge(e, this->backward);
+//       }
+//     };
+
+//     using GraphWrapper<Graph>::first;
+// //     NodeIt& first(NodeIt& i) const { 
+// //       i=NodeIt(*this); return i;
+// //     }
+//     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
+//       i=OutEdgeIt(*this, p); return i;
+//     }
+// //    FIXME not tested
+//     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
+//       i=InEdgeIt(*this, p); return i;
+//     }
+//     EdgeIt& first(EdgeIt& i) const { 
+//       i=EdgeIt(*this); return i;
+//     }
+  
+//     using GraphWrapper<Graph>::next;
+// //    NodeIt& next(NodeIt& n) const { GraphWrapper<Graph>::next(n); return n; }
+//     OutEdgeIt& next(OutEdgeIt& e) const { 
+//       if (!e.backward) {
+// 	Node v=this->graph->aNode(e.out);
+// 	this->graph->next(e.out);
+// 	while(this->graph->valid(e.out) && !enabled(e)) { 
+// 	  this->graph->next(e.out); }
+// 	if (!this->graph->valid(e.out)) {
+// 	  e.backward=true;
+// 	  this->graph->first(e.in, v); 
+// 	  while(this->graph->valid(e.in) && !enabled(e)) { 
+// 	    this->graph->next(e.in); }
+// 	}
+//       } else {
+// 	this->graph->next(e.in);
+// 	while(this->graph->valid(e.in) && !enabled(e)) { 
+// 	  this->graph->next(e.in); } 
+//       }
+//       return e;
+//     }
+// //     FIXME Not tested
+//     InEdgeIt& next(InEdgeIt& e) const { 
+//       if (!e.backward) {
+// 	Node v=this->graph->aNode(e.in);
+// 	this->graph->next(e.in);
+// 	while(this->graph->valid(e.in) && !enabled(e)) { 
+// 	  this->graph->next(e.in); }
+// 	if (!this->graph->valid(e.in)) {
+// 	  e.backward=true;
+// 	  this->graph->first(e.out, v); 
+// 	  while(this->graph->valid(e.out) && !enabled(e)) { 
+// 	    this->graph->next(e.out); }
+// 	}
+//       } else {
+// 	this->graph->next(e.out);
+// 	while(this->graph->valid(e.out) && !enabled(e)) { 
+// 	  this->graph->next(e.out); } 
+//       }
+//       return e;
+//     }
+//     EdgeIt& next(EdgeIt& e) const {
+//       if (!e.backward) {
+// 	this->graph->next(e.e);
+// 	while(this->graph->valid(e.e) && !enabled(e)) { 
+// 	  this->graph->next(e.e); }
+// 	if (!this->graph->valid(e.e)) {
+// 	  e.backward=true;
+// 	  this->graph->first(e.e); 
+// 	  while(this->graph->valid(e.e) && !enabled(e)) { 
+// 	    this->graph->next(e.e); }
+// 	}
+//       } else {
+// 	this->graph->next(e.e);
+// 	while(this->graph->valid(e.e) && !enabled(e)) { 
+// 	  this->graph->next(e.e); } 
+//       }
+//       return e;
+//     }
+
+//     Node tail(Edge e) const { 
+//       return ((!e.backward) ? this->graph->tail(e) : this->graph->head(e)); }
+//     Node head(Edge e) const { 
+//       return ((!e.backward) ? this->graph->head(e) : this->graph->tail(e)); }
+
+//     Node aNode(OutEdgeIt e) const { 
+//       return ((!e.backward) ? this->graph->aNode(e.out) : 
+// 	      this->graph->aNode(e.in)); }
+//     Node bNode(OutEdgeIt e) const { 
+//       return ((!e.backward) ? this->graph->bNode(e.out) : 
+// 	      this->graph->bNode(e.in)); }
+
+//     Node aNode(InEdgeIt e) const { 
+//       return ((!e.backward) ? this->graph->aNode(e.in) : 
+// 	      this->graph->aNode(e.out)); }
+//     Node bNode(InEdgeIt e) const { 
+//       return ((!e.backward) ? this->graph->bNode(e.in) : 
+// 	      this->graph->bNode(e.out)); }
+
+//     /// Gives back the opposite edge.
+//     Edge opposite(const Edge& e) const { 
+//       Edge f=e;
+//       f.backward=!f.backward;
+//       return f;
+//     }
+
+// //    int nodeNum() const { return graph->nodeNum(); }
+//     //FIXME
+//     void edgeNum() const { }
+//     //int edgeNum() const { return graph->edgeNum(); }
+
+
+// //    int id(Node v) const { return graph->id(v); }
+
+//     bool valid(Node n) const { return GraphWrapper<Graph>::valid(n); }
+//     bool valid(Edge e) const { 
+//       return this->graph->valid(e);
+// 	//return e.forward ? graph->valid(e.out) : graph->valid(e.in); 
+//     }
+
+//     bool forward(const Edge& e) const { return !e.backward; }
+//     bool backward(const Edge& e) const { return e.backward; }
+
+// //     void augment(const Edge& e, Number a) const {
+// //       if (!e.backward)  
+// // // 	flow->set(e.out, flow->get(e.out)+a);
+// // 	flow->set(e, (*flow)[e]+a);
+// //       else  
+// // // 	flow->set(e.in, flow->get(e.in)-a);
+// // 	flow->set(e, (*flow)[e]-a);
+// //     }
+
+//     bool enabled(const Edge& e) const { 
+//       if (!e.backward) 
+// //	return (capacity->get(e.out)-flow->get(e.out)); 
+// 	//return ((*capacity)[e]-(*flow)[e]);
+// 	return true;
+//       else 
+// //	return (flow->get(e.in)); 
+// 	//return ((*flow)[e]); 
+// 	return true;
+//     }
+
+// //     Number enabled(typename Graph::OutEdgeIt out) const { 
+// // //      return (capacity->get(out)-flow->get(out)); 
+// //       return ((*capacity)[out]-(*flow)[out]); 
+// //     }
+    
+// //     Number enabled(typename Graph::InEdgeIt in) const { 
+// // //      return (flow->get(in)); 
+// //       return ((*flow)[in]); 
+// //     }
+
+//     template <typename T>
+//     class EdgeMap {
+//       typename Graph::template EdgeMap<T> forward_map, backward_map; 
+//     public:
+//       typedef T ValueType;
+//       typedef Edge KeyType;
+//       EdgeMap(const BidirGraphWrapper<Graph>& _G) : forward_map(*(_G.graph)), backward_map(*(_G.graph)) { }
+//       EdgeMap(const BidirGraphWrapper<Graph>& _G, T a) : forward_map(*(_G.graph), a), backward_map(*(_G.graph), a) { }
+//       void set(Edge e, T a) { 
+// 	if (!e.backward) 
+// 	  forward_map.set(e/*.out*/, a); 
+// 	else 
+// 	  backward_map.set(e/*.in*/, a); 
+//       }
+//       T operator[](Edge e) const { 
+// 	if (!e.backward) 
+// 	  return forward_map[e/*.out*/]; 
+// 	else 
+// 	  return backward_map[e/*.in*/]; 
+//       }
+//       void update() { 
+// 	forward_map.update(); 
+// 	backward_map.update();
+//       }
+// //       T get(Edge e) const { 
+// // 	if (e.out_or_in) 
+// // 	  return forward_map.get(e.out); 
+// // 	else 
+// // 	  return backward_map.get(e.in); 
+// //       }
+//     };
+//   };
 
   /// \brief A bidirected graph template.
@@ -942,4 +1365,5 @@
   template<typename Graph>
   class BidirGraph : public BidirGraphWrapper<Graph> {
+  public:
     typedef UndirGraphWrapper<Graph> Parent;
   protected:
@@ -950,4 +1374,151 @@
     }
   };
+
+
+
+  /// An experiment for ResGraphWrapper.
+  template<typename Graph, typename Number,
+	   typename CapacityMap, typename FlowMap>
+  class ForwardFilter {
+    const Graph* graph;
+    const CapacityMap* capacity;
+    const FlowMap* flow;
+  public:
+    ForwardFilter(const Graph& _graph, 
+		  const CapacityMap& _capacity, const FlowMap& _flow) :
+      graph(&_graph), capacity(&_capacity), flow(&_flow) { }
+    bool operator[](const typename Graph::Edge& e) const {
+      return ((*flow)[e] < (*capacity)[e]);
+    }
+  };
+
+  /// An experiment for ResGraphWrapper.
+  template<typename Graph, typename Number,
+	   typename CapacityMap, typename FlowMap>
+  class BackwardFilter {
+    const Graph* graph;
+    const CapacityMap* capacity;
+    const FlowMap* flow;
+  public:
+    BackwardFilter(const Graph& _graph, 
+		   const CapacityMap& _capacity, const FlowMap& _flow) :
+      graph(&_graph), capacity(&_capacity), flow(&_flow) { }
+    bool operator[](const typename Graph::Edge& e) const {
+      return (0 < (*flow)[e]);
+    }
+  };
+
+
+  /// An experiment for ResGraphWrapper.
+  template<typename Graph, typename Number, 
+	   typename CapacityMap, typename FlowMap>
+  class ExpResGraphWrapper : 
+    public SubBidirGraphWrapper< 
+    Graph, 
+    ForwardFilter<Graph, Number, CapacityMap, FlowMap>,  
+    BackwardFilter<Graph, Number, CapacityMap, FlowMap> > {
+  public:
+    typedef SubBidirGraphWrapper< 
+      Graph, 
+      ForwardFilter<Graph, Number, CapacityMap, FlowMap>,  
+      BackwardFilter<Graph, Number, CapacityMap, FlowMap> > Parent;
+  protected:
+    const CapacityMap* capacity;
+    FlowMap* flow;
+    ForwardFilter<Graph, Number, CapacityMap, FlowMap> forward_filter;
+    BackwardFilter<Graph, Number, CapacityMap, FlowMap> backward_filter;
+  public:
+    ExpResGraphWrapper(Graph& _graph, const CapacityMap& _capacity, 
+		       FlowMap& _flow) : 
+      Parent(), capacity(&_capacity), flow(&_flow), 
+      forward_filter(_graph, _capacity, _flow), 
+      backward_filter(_graph, _capacity, _flow) {
+      Parent::setGraph(_graph);
+      Parent::setForwardFilterMap(forward_filter);
+      Parent::setBackwardFilterMap(backward_filter);
+    }
+
+    //    bool forward(const Parent::Edge& e) const { return Parent::forward(e); }
+    //bool backward(const Edge& e) const { return e.backward; }
+
+    void augment(const typename Parent::Edge& e, Number a) const {
+      if (Parent::forward(e))  
+// 	flow->set(e.out, flow->get(e.out)+a);
+	flow->set(e, (*flow)[e]+a);
+      else  
+	//flow->set(e.in, flow->get(e.in)-a);
+	flow->set(e, (*flow)[e]-a);
+    }
+
+    Number resCap(const typename Parent::Edge& e) const { 
+      if (Parent::forward(e)) 
+//	return (capacity->get(e.out)-flow->get(e.out)); 
+	return ((*capacity)[e]-(*flow)[e]); 
+      else 
+//	return (flow->get(e.in)); 
+	return ((*flow)[e]); 
+    }
+
+  };
+
+
+
+
+//   /// An experiment for ResGraphWrapper.
+//   template<typename Graph, typename Number, 
+// 	   typename CapacityMap, typename FlowMap>
+//   class ExpResGraphWrapper : 
+//     public SubGraphWrapper< BidirGraphWrapper<Graph>, 
+// 			    ConstMap<typename BidirGraphWrapper<Graph>::Node, 
+// 				     bool>, 
+// 			    EdgeFilter< BidirGraphWrapper<Graph>, 
+// 					CapacityMap, FlowMap> > {
+//   public:
+//     typedef SubGraphWrapper< BidirGraphWrapper<Graph>, 
+// 			     ConstMap<typename BidirGraphWrapper<Graph>::Node, 
+// 				      bool>, 
+// 			     EdgeFilter< BidirGraphWrapper<Graph>, 
+// 					 CapacityMap, FlowMap> > Parent; 
+//   protected:
+//     const CapacityMap* capacity;
+//     FlowMap* flow;
+//     BidirGraphWrapper<Graph> bidir_graph;
+//     ConstMap<typename BidirGraphWrapper<Graph>::Node, bool> node_filter;
+//     EdgeFilter< BidirGraphWrapper<Graph>, CapacityMap, FlowMap> edge_filter;
+//   public:
+//     ExpResGraphWrapper(Graph& _graph, const CapacityMap& _capacity, 
+// 		       FlowMap& _flow) : 
+//       Parent(), capacity(&_capacity), flow(&_flow), 
+//       bidir_graph(_graph), 
+//       node_filter(true),
+//       edge_filter(bidir_graph, *capacity, *flow) { 
+//       Parent::setGraph(bidir_graph);
+//       Parent::setNodeFilterMap(node_filter);
+//       Parent::setEdgeFilterMap(edge_filter);
+//     }
+
+//     //    bool forward(const Parent::Edge& e) const { return Parent::forward(e); }
+//     //bool backward(const Edge& e) const { return e.backward; }
+
+//     void augment(const typename Parent::Edge& e, Number a) const {
+//       if (Parent::forward(e))  
+// // 	flow->set(e.out, flow->get(e.out)+a);
+// 	flow->set(e, (*flow)[e]+a);
+//       else  
+// // 	flow->set(e.in, flow->get(e.in)-a);
+// 	flow->set(e, (*flow)[e]-a);
+//     }
+
+//     Number resCap(const typename Parent::Edge& e) const { 
+//       if (Parent::forward(e)) 
+// //	return (capacity->get(e.out)-flow->get(e.out)); 
+// 	return ((*capacity)[e]-(*flow)[e]); 
+//       else 
+// //	return (flow->get(e.in)); 
+// 	return ((*flow)[e]); 
+//     }
+
+//   };
+
 
 
@@ -958,4 +1529,6 @@
 	   typename CapacityMap, typename FlowMap>
   class ResGraphWrapper : public GraphWrapper<Graph> {
+  public:
+    typedef GraphWrapper<Graph> Parent; 
   protected:
     const CapacityMap* capacity;
@@ -1284,4 +1857,6 @@
   template<typename Graph, typename FirstOutEdgesMap>
   class ErasingFirstGraphWrapper : public GraphWrapper<Graph> {
+  public:
+    typedef GraphWrapper<Graph> Parent; 
   protected:
     FirstOutEdgesMap* first_out_edges;