diff -r 0baae4311a9f -r b9556a055632 src/HOL/Library/Nat_Bijection.thy
--- a/src/HOL/Library/Nat_Bijection.thy	Sun Nov 02 17:16:01 2014 +0100
+++ b/src/HOL/Library/Nat_Bijection.thy	Sun Nov 02 17:20:45 2014 +0100
@@ -6,7 +6,7 @@
     Author:     Alexander Krauss
 *)
 
-header {* Bijections between natural numbers and other types *}
+section {* Bijections between natural numbers and other types *}
 
 theory Nat_Bijection
 imports Main