Index: src/work/marci/graph_wrapper.h
===================================================================
--- src/work/marci/graph_wrapper.h	(revision 236)
+++ src/work/marci/graph_wrapper.h	(revision 237)
@@ -329,6 +329,13 @@
   class RevGraphWrapper : public GraphWrapperSkeleton<GraphWrapper> {
   public:
+    typedef typename GraphWrapperSkeleton<GraphWrapper>::Node Node;
+    typedef typename GraphWrapperSkeleton<GraphWrapper>::Edge Edge;
     typedef typename GraphWrapperSkeleton<GraphWrapper>::OutEdgeIt InEdgeIt;
     typedef typename GraphWrapperSkeleton<GraphWrapper>::InEdgeIt OutEdgeIt;
+
+    Node head(const Edge& e) const 
+      { return GraphWrapperSkeleton<GraphWrapper>::tail(e); }
+    Node tail(const Edge& e) const 
+      { return GraphWrapperSkeleton<GraphWrapper>::head(e); }
     
     RevGraphWrapper(GraphWrapper _gw) :