fix module problems (obs from Paulo Moura).

library/apply_macros.yap

@@ -4,6 +4,8 @@
 %   Purpose: Macros to apply a predicate to all elements
 %            of a list or to all sub-terms of a term.
 
+:- module(apply_macros, []).
+
 :- reexport(maplist, [selectlist/3,
 			 checklist/2,
 			 maplist/2,

library/wundgraphs.yap

@@ -46,8 +46,7 @@
 	    wdgraph_del_edges/3,
 	    wdgraph_del_vertex/3,
 	    wdgraph_edges/2,
-	    wdgraph_neighbors/3,
-	    wdgraph_symmetric_closure/2
+	    wdgraph_neighbors/3
 	   ]).
 
 :- use_module(library(rbtrees),