src/HOL/Library/Prefix_Order.thy

--- a/src/HOL/Library/Prefix_Order.thy	Sun Nov 02 17:16:01 2014 +0100
+++ b/src/HOL/Library/Prefix_Order.thy	Sun Nov 02 17:20:45 2014 +0100
@@ -2,7 +2,7 @@
     Author:     Tobias Nipkow and Markus Wenzel, TU Muenchen
 *)
 
-header {* Prefix order on lists as order class instance *}
+section {* Prefix order on lists as order class instance *}
 
 theory Prefix_Order
 imports Sublist