--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/AxClasses/Tutorial/Xor.thy	Fri Sep 01 14:27:36 1995 +0200
@@ -0,0 +1,15 @@
+(*  Title:      HOL/AxClasses/Tutorial/Xor.thy
+    ID:         $Id$
+    Author:     Markus Wenzel, TU Muenchen
+
+Define overloaded constants "<*>", "inv", "1" on type "bool".
+*)
+
+Xor = Group +
+
+defs
+  prod_bool_def "x <*> y == x ~= (y::bool)"
+  inv_bool_def  "inv x   == x::bool"
+  unit_bool_def "1       == False"
+
+end