diff -r cefceb54c656 -r c7faa011bfa7 src/HOL/Proofs/Lambda/Commutation.thy
--- a/src/HOL/Proofs/Lambda/Commutation.thy	Thu Feb 16 17:09:15 2012 +0100
+++ b/src/HOL/Proofs/Lambda/Commutation.thy	Thu Feb 16 22:18:28 2012 +0100
@@ -7,7 +7,7 @@
 
 theory Commutation imports Main begin
 
-declare [[syntax_ambiguity_level = 100]]
+declare [[syntax_ambiguity = ignore]]
 
 
 subsection {* Basic definitions *}