diff -r db33de6cb570 -r c6849a634582 Nominal/LamEx.thy
--- a/Nominal/LamEx.thy	Fri Mar 19 12:24:16 2010 +0100
+++ b/Nominal/LamEx.thy	Fri Mar 19 12:28:35 2010 +0100
@@ -41,10 +41,6 @@
   "\<not>(P \<and> Q) \<longleftrightarrow> (\<not>P) \<or> (\<not>Q)"
   by simp
 
-lemma infinite_Un:
-  "infinite (S \<union> T) \<longleftrightarrow> infinite S \<or> infinite T"
-  by simp
-
 instance
 apply default
 apply(induct_tac x)