diff -r 9537bf1c4853 -r 5b7a9633cfa8 src/LCF/ex/Ex3.thy
--- a/src/LCF/ex/Ex3.thy	Sun Nov 02 18:21:14 2014 +0100
+++ b/src/LCF/ex/Ex3.thy	Sun Nov 02 18:21:45 2014 +0100
@@ -1,4 +1,4 @@
-header {* Addition with fixpoint of successor *}
+section {* Addition with fixpoint of successor *}
 
 theory Ex3
 imports LCF