--- a/src/HOL/Map.thy Wed Apr 16 22:14:08 2003 +0200
+++ b/src/HOL/Map.thy Wed Apr 16 22:21:32 2003 +0200
@@ -6,6 +6,8 @@
The datatype of `maps' (written ~=>); strongly resembles maps in VDM.
*)
+header {* Maps *}
+
theory Map = List:
types ('a,'b) "~=>" = "'a => 'b option" (infixr 0)