diff -r b8a07a3c1692 -r ae54ce4cde54 Nominal/FSet.thy
--- a/Nominal/FSet.thy	Sat Mar 27 13:50:59 2010 +0100
+++ b/Nominal/FSet.thy	Sat Mar 27 14:38:22 2010 +0100
@@ -424,4 +424,7 @@
   | dest_fsetT T = raise TYPE ("dest_fsetT: fset type expected", [T], []);
 *}
 
+no_notation
+  list_eq (infix "\<approx>" 50)
+
 end