src/ZF/AC/AC18_AC19.thy

Krzysztof Grabczewski's (nearly) complete AC proofs

(*  Title: 	ZF/AC/AC18_AC19.thy
    ID:         $Id$
    Author: 	Krzysztof Gr`abczewski

Additional definition used in the proof AC19 ==> AC1 which is a part
of the chain AC1 ==> AC18 ==> AC19 ==> AC1
*)

AC18_AC19 = AC_Equiv +

consts
  u_    :: "i => i"
  
defs

  u_def "u_(a) == {c Un {0}. c:a}"

end