--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ex/puzzle.thy	Thu Sep 16 12:21:07 1993 +0200
@@ -0,0 +1,12 @@
+(*  Title: 	HOL/ex/puzzle.thy
+    ID:         $Id$
+    Author: 	Tobias Nipkow
+    Copyright   1993 TU Muenchen
+
+An question from "Bundeswettbewerb Mathematik"
+*)
+
+Puzzle = Nat +
+consts f :: "nat => nat"
+rules  f_ax "f(f(n)) < f(Suc(n))"
+end