diff -r 4cd528a30ec1 -r b6a68c15a6a3 doc/graphs.dox
--- a/doc/graphs.dox	Fri Jun 30 12:14:36 2006 +0000
+++ b/doc/graphs.dox	Fri Jun 30 12:15:45 2006 +0000
@@ -9,20 +9,20 @@
 The primary data structures of LEMON are the graph classes. They all
 provide a node list - edge list interface, i.e. they have
 functionalities to list the nodes and the edges of the graph as well
-as  incoming and outgoing edges of a given node. This functionalities
-are defined in the \ref lemon::concept::Graph "Graph" concept.
+as  incoming and outgoing edges of a given node. 
 
-The next important graph type concept is the undirected graph concept
-what is defined in the \ref lemon::concept::UGraph "UGraph" concept class.
-Each undirected graphs provide node - undirected edge list interfaces.
-In addition the undirected graphs can be used as directed graphs so
-they are also conform to the \ref lemon::concept::Graph "Graph" concept.
+Each graph should meet the \ref lemon::concept::Graph "Graph" concept.
+This concept does not make it possible to change the graph (i.e. it is
+not possible to add or delete edges or nodes). Most of the graph
+algorithms will run on these graphs.
 
-Usually the graphs can be sorted to two group, the first is the
-general topology graph types which can store any graph and the second
-are the special topology graphs like the \ref FullUGraph or the \ref
-GridUGraph.
 
+In case of graphs meeting the full feature
+\ref lemon::concept::ErasableGraph "ErasableGraph"
+concept
+you can also erase individual edges and nodes in arbitrary order.
+
+The implemented graph structures are the following.
 \li \ref lemon::ListGraph "ListGraph" is the most versatile graph class. It meets
 the \ref lemon::concept::ErasableGraph "ErasableGraph" concept
 and it also has some convenient extra features.