diff -r 19efc2af3e6c -r f967a16dfcdd src/HOL/Big_Operators.thy
--- a/src/HOL/Big_Operators.thy	Mon Sep 06 22:58:06 2010 +0200
+++ b/src/HOL/Big_Operators.thy	Tue Sep 07 10:05:19 2010 +0200
@@ -1504,11 +1504,11 @@
 
 lemma dual_max:
   "ord.max (op \<ge>) = min"
-  by (auto simp add: ord.max_def_raw min_def expand_fun_eq)
+  by (auto simp add: ord.max_def_raw min_def ext_iff)
 
 lemma dual_min:
   "ord.min (op \<ge>) = max"
-  by (auto simp add: ord.min_def_raw max_def expand_fun_eq)
+  by (auto simp add: ord.min_def_raw max_def ext_iff)
 
 lemma strict_below_fold1_iff:
   assumes "finite A" and "A \<noteq> {}"