diff -r 3ebc7ecfb0dd -r 78623a0f294b Nominal/Nominal2_Base.thy
--- a/Nominal/Nominal2_Base.thy	Sat Nov 27 22:55:29 2010 +0000
+++ b/Nominal/Nominal2_Base.thy	Sat Nov 27 23:00:16 2010 +0000
@@ -1310,7 +1310,7 @@
   and   S::"'a fset"
   shows "supp (insert_fset x S) = supp x \<union> supp S"
   apply(subst supp_fset[symmetric])
-  apply(simp add: supp_fset supp_of_finite_insert)
+  apply(simp add: supp_of_finite_insert)
   done
 
 lemma fset_finite_supp: