author lcp
Fri, 14 Apr 1995 12:03:15 +0200
changeset 1061 8897213195c0
child 1450 19a256c8086d
permissions -rw-r--r--
Definition of 'let' declarations, from HOL

(*  Title: 	ZF/Let
    ID:         $Id$
    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1995  University of Cambridge

Let expressions -- borrowed from HOL

open Let;

val [prem] = goalw thy
    [Let_def] "(!!x. x=t ==> P(u(x))) ==> P(let x=t in u(x))";
br (refl RS prem) 1;
qed "letI";