src/ZF/Let.ML

added ignored_consts, thms_containing, add_store_axioms(_i),
add_store_defs(_i), thms_of;
tuned pure thys;

(*  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";