lfp.thy
author lcp
Wed, 25 May 1994 12:43:50 +0200
changeset 76 fb4fe9f8c3cd
parent 0 7949f97df77a
permissions -rw-r--r--
HOL/equalities: added some identities from ZF/equalities HOL/equalities/constant_UN: renamed UN1_constant HOL/equalities/Union_Un_distrib: deleted duplicate! HOL/equalities/Union_Int_subset: new

(*  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