--- a/Nominal/Nominal2_Base.thy	Mon May 19 16:45:46 2014 +0100
+++ b/Nominal/Nominal2_Base.thy	Mon Jul 07 10:21:40 2014 +0100
@@ -373,12 +373,12 @@
 lemma permute_self: 
   shows "p \<bullet> p = p"
   unfolding permute_perm_def 
-  by (simp add: add_assoc)
+  by (simp add: add.assoc)
 
 lemma pemute_minus_self:
   shows "- p \<bullet> p = p"
   unfolding permute_perm_def 
-  by (simp add: add_assoc)
+  by (simp add: add.assoc)
 
 
 subsection {* Permutations for functions *}