diff -r 76c5f277b234 -r f2a587696afb src/Tools/Code/code_simp.ML
--- a/src/Tools/Code/code_simp.ML	Wed Nov 23 22:07:55 2011 +0100
+++ b/src/Tools/Code/code_simp.ML	Wed Nov 23 22:59:39 2011 +0100
@@ -36,7 +36,8 @@
 (* build simpset and conversion from program *)
 
 fun add_stmt (Code_Thingol.Fun (_, ((_, eqs), some_cong))) ss =
-      ss addsimps (map_filter (fst o snd)) eqs addcongs (the_list some_cong)
+      ss addsimps (map_filter (fst o snd)) eqs
+      |> fold Simplifier.add_cong (the_list some_cong)
   | add_stmt (Code_Thingol.Classinst (_, (_, (classparam_instances, _)))) ss =
       ss addsimps (map (fst o snd) classparam_instances)
   | add_stmt _ ss = ss;