diff -r 9537bf1c4853 -r 5b7a9633cfa8 src/HOL/Transitive_Closure.thy
--- a/src/HOL/Transitive_Closure.thy	Sun Nov 02 18:21:14 2014 +0100
+++ b/src/HOL/Transitive_Closure.thy	Sun Nov 02 18:21:45 2014 +0100
@@ -3,7 +3,7 @@
     Copyright   1992  University of Cambridge
 *)
 
-header {* Reflexive and Transitive closure of a relation *}
+section {* Reflexive and Transitive closure of a relation *}
 
 theory Transitive_Closure
 imports Relation