--- a/src/ZF/Bool.thy Sun Nov 02 16:09:35 2014 +0100
+++ b/src/ZF/Bool.thy Sun Nov 02 16:39:54 2014 +0100
@@ -3,7 +3,7 @@
Copyright 1992 University of Cambridge
*)
-header{*Booleans in Zermelo-Fraenkel Set Theory*}
+section{*Booleans in Zermelo-Fraenkel Set Theory*}
theory Bool imports pair begin