src/ZF/AC.thy
author paulson
Fri, 16 Feb 1996 18:00:47 +0100
changeset 1512 ce37c64244c0
parent 1478 2b8c2a7547ab
child 2469 b50b8c0eec01
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/AC.thy
    ID:         $Id$
    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1994  University of Cambridge

The Axiom of Choice

This definition comes from Halmos (1960), page 59.
*)

AC = ZF + "func" +
rules
  AC    "[| a: A;  !!x. x:A ==> (EX y. y:B(x)) |] ==> EX z. z : Pi(A,B)"
end