src/HOL/Gfp.thy
author clasohm
Tue, 21 Nov 1995 12:41:52 +0100
changeset 1350 5bf4a54ba25f
parent 923 ff1574a81019
child 1370 7361ac9b024d
permissions -rw-r--r--
replaced exit_use by exit_use_dir for subdirectories

(*  Title: 	HOL/gfp.thy
    ID:         $Id$
    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1994  University of Cambridge

Greatest fixed points (requires Lfp too!)
*)

Gfp = Lfp +
consts gfp :: "['a set=>'a set] => 'a set"
defs
 (*greatest fixed point*)
 gfp_def "gfp(f) == Union({u. u <= f(u)})"
end