diff -r db866dc081f8 -r 7172c7ffb047 src/HOL/Word/Bits_Bit.thy
--- a/src/HOL/Word/Bits_Bit.thy	Sun Nov 02 16:50:42 2014 +0100
+++ b/src/HOL/Word/Bits_Bit.thy	Sun Nov 02 16:54:06 2014 +0100
@@ -2,7 +2,7 @@
     Author:     Author: Brian Huffman, PSU and Gerwin Klein, NICTA
 *)
 
-header {* Bit operations in $\cal Z_2$ *}
+section {* Bit operations in $\cal Z_2$ *}
 
 theory Bits_Bit
 imports Bits "~~/src/HOL/Library/Bit"