--- a/src/Pure/Isar/proof_context.ML Mon Feb 06 11:00:24 2006 +0100
+++ b/src/Pure/Isar/proof_context.ML Mon Feb 06 11:01:28 2006 +0100
@@ -1115,7 +1115,7 @@
val (ys, zs) = split_list (fixes_of ctxt);
val (vars, ctxt') = prep raw_vars ctxt;
val xs = map #1 vars;
- val _ = no_dups ctxt (duplicates xs);
+ val _ = no_dups ctxt (gen_duplicates (op =) xs);
val xs' =
if is_body ctxt then Term.variantlist (map Syntax.skolem xs, zs)
else (no_dups ctxt (xs inter_string ys); no_dups ctxt (xs inter_string zs); xs);