--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/CCL/lfp.thy	Thu Sep 16 12:20:38 1993 +0200
@@ -0,0 +1,14 @@
+(*  Title: 	HOL/lfp.thy
+    ID:         $Id$
+    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
+    Copyright   1992  University of Cambridge
+
+The Knaster-Tarski Theorem
+*)
+
+Lfp = Set +
+consts lfp :: "['a set=>'a set] => 'a set"
+rules
+ (*least fixed point*)
+ lfp_def "lfp(f) == Inter({u. f(u) <= u})"
+end