author paulson
Fri, 16 Feb 1996 18:00:47 +0100
changeset 1512 ce37c64244c0
parent 1461 6bcb44e4d6e5
child 9907 473a6604da94
permissions -rw-r--r--
Elimination of fully-functorial style. Type tactic changed to a type abbrevation (from a datatype). Constructor tactic and function apply deleted.

(*  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))";
by (rtac (refl RS prem) 1);
qed "LetI";