diff -r 9537bf1c4853 -r 5b7a9633cfa8 src/CTT/Bool.thy
--- a/src/CTT/Bool.thy	Sun Nov 02 18:21:14 2014 +0100
+++ b/src/CTT/Bool.thy	Sun Nov 02 18:21:45 2014 +0100
@@ -3,7 +3,7 @@
     Copyright   1991  University of Cambridge
 *)
 
-header {* The two-element type (booleans and conditionals) *}
+section {* The two-element type (booleans and conditionals) *}
 
 theory Bool
 imports CTT