Lfp.thy
author lcp
Tue, 06 Sep 1994 10:54:46 +0200
changeset 134 4b7da5a895e7
parent 116 ab4328bbff70
child 178 12dd5d2e266b
permissions -rw-r--r--
HOL/ind_syntax/factors: now returns only factors in the product type that associate to the right. Previously the proof of the induction rule crashed on types such as (bool*bool)*bool.

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

The Knaster-Tarski Theorem
*)

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