--- a/src/HOL/Isar_Examples/Puzzle.thy Sun Nov 02 17:20:45 2014 +0100
+++ b/src/HOL/Isar_Examples/Puzzle.thy Sun Nov 02 17:23:48 2014 +0100
@@ -1,4 +1,4 @@
-header \<open>An old chestnut\<close>
+section \<open>An old chestnut\<close>
theory Puzzle
imports Main