lfp.thy
author lcp
Thu, 21 Jul 1994 10:52:00 +0200
changeset 97 3f4976d8c97f
parent 0 7949f97df77a
permissions -rw-r--r--
HOL/Makefile: now test depends upon SUBST_FILES HOL/Makefile/SUBST_FILES: changed some filenames to upper case HOL/Makefile: now executes ex/ROOT.ML after Subst/ROOT.ML

(*  Title: 	HOL/lfp.thy
    ID:         $Id$
    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1992  University of Cambridge

The Knaster-Tarski Theorem
*)

Lfp = Sum +
consts lfp :: "['a set=>'a set] => 'a set"
rules
 (*least fixed point*)
 lfp_def "lfp(f) == Inter({u. f(u) <= u})"
end