Lfp.thy
author nipkow
Tue, 16 Aug 1994 09:57:51 +0200
changeset 104 a0e6613dfbee
parent 0 7949f97df77a
child 116 ab4328bbff70
permissions -rw-r--r--
allow long_id for reference to type in primrec. Doesn't work yet, though, because of problems with the autoloader.

(*  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