src/CCL/Lfp.thy
author wenzelm
Thu, 15 Nov 2001 18:20:13 +0100
changeset 12207 4dff931b852f
parent 1474 3f7d67927fe2
child 17456 bcf7544875b2
permissions -rw-r--r--
added Induct/Binary_Trees.thy, Induct/Tree_Forest (converted from former ex/TF.ML ex/TF.thy ex/Term.ML ex/Term.thy);

(*  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