src/Pure/axclass.ML

--- a/src/Pure/axclass.ML	Sat Oct 13 20:31:05 2001 +0200
+++ b/src/Pure/axclass.ML	Sat Oct 13 20:31:34 2001 +0200
@@ -440,7 +440,7 @@
 
 fun inst_proof mk_prop add_thms (sig_prop, comment) int thy =
   thy
-  |> IsarThy.theorem_i ((("", [inst_attribute add_thms]),
+  |> IsarThy.theorem_i Drule.internalK ((("", [inst_attribute add_thms]),
     (mk_prop (Theory.sign_of thy) sig_prop, ([], []))), comment) int;
 
 val instance_subclass_proof = inst_proof (mk_classrel oo read_classrel) add_classrel_thms;