src/Pure/axclass.ML

--- a/src/Pure/axclass.ML	Tue Sep 20 08:20:22 2005 +0200
+++ b/src/Pure/axclass.ML	Tue Sep 20 08:21:49 2005 +0200
@@ -103,7 +103,7 @@
         Type (t, tys) => (t, map dest_varT tys handle TYPE _ => err ())
       | _ => err ());
     val ss =
-      if null (gen_duplicates eq_fst tvars)
+      if null (gen_duplicates (eq_fst (op =)) tvars)
       then map snd tvars else err ();
   in (t, ss, c) end;