diff -r 7a518df79892 -r 891f99700ea1 src/hugo/list_graph.h
--- a/src/hugo/list_graph.h	Mon Jul 19 13:32:28 2004 +0000
+++ b/src/hugo/list_graph.h	Tue Jul 20 09:43:12 2004 +0000
@@ -137,13 +137,13 @@
     Node bNode(OutEdgeIt e) const { return edges[e.n].head; }
     Node bNode(InEdgeIt e) const { return edges[e.n].tail; }
 
-    NodeIt& first(NodeIt& v) const { 
+    static NodeIt& first(NodeIt& v) const { 
       v=NodeIt(*this); return v; }
-    EdgeIt& first(EdgeIt& e) const { 
+    static EdgeIt& first(EdgeIt& e) const { 
       e=EdgeIt(*this); return e; }
-    OutEdgeIt& first(OutEdgeIt& e, const Node v) const { 
+    static OutEdgeIt& first(OutEdgeIt& e, const Node v) const { 
       e=OutEdgeIt(*this,v); return e; }
-    InEdgeIt& first(InEdgeIt& e, const Node v) const { 
+    static InEdgeIt& first(InEdgeIt& e, const Node v) const { 
       e=InEdgeIt(*this,v); return e; }
 
 //     template< typename It >
@@ -152,13 +152,13 @@
 //     template< typename It >
 //     It first(Node v) const { It e; first(e,v); return e; }
 
-    bool valid(Edge e) const { return e.n!=-1; }
-    bool valid(Node n) const { return n.n!=-1; }
+    static bool valid(Edge e) const { return e.n!=-1; }
+    static bool valid(Node n) const { return n.n!=-1; }
     
-    void setInvalid(Edge &e) { e.n=-1; }
-    void setInvalid(Node &n) { n.n=-1; }
+    static void setInvalid(Edge &e) { e.n=-1; }
+    static void setInvalid(Node &n) { n.n=-1; }
     
-    template <typename It> It getNext(It it) const
+    template <typename It> static It getNext(It it) const
     { It tmp(it); return next(tmp); }
 
     NodeIt& next(NodeIt& it) const { 
@@ -183,8 +183,8 @@
       return it;
     }
 
-    int id(Node v) const { return v.n; }
-    int id(Edge e) const { return e.n; }
+    static int id(Node v) const { return v.n; }
+    static int id(Edge e) const { return e.n; }
 
     /// Adds a new node to the graph.
 
@@ -627,7 +627,7 @@
 
     ///Returns the oppositely directed
     ///pair of the edge \c e.
-    Edge opposite(Edge e) const
+    static Edge opposite(Edge e) const
     {
       Edge f;
       f.idref() = e.idref() - 2*(e.idref()%2) + 1;