src/ZF/Let.ML
changeset 1061 8897213195c0
child 1450 19a256c8086d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/ZF/Let.ML	Fri Apr 14 12:03:15 1995 +0200
@@ -0,0 +1,14 @@
+(*  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";