handle case where system:goal_expansion/2 is undefined.

2011-02-15 07:51:12 -08:00 · 2011-02-15 07:51:12 -08:00 · cd028bbd3f
parent 82f3af4f23
commit cd028bbd3f
1 changed files with 1 additions and 0 deletions
--- a/pl/modules.yap
+++ b/pl/modules.yap
@ -327,6 +327,7 @@ expand_goal(G, G).
 	 true
 	;
 	 recorded('$dialect',swi,_),
+	 '$pred_exists'(goal_expansion(G,GI), system),
 	 system:goal_expansion(G, GI)
 	->
 	  true