src/ZF/AC.thy
author lcp
Tue Jul 26 13:21:20 1994 +0200 (1994-07-26)
changeset 484 70b789956bd3
child 1478 2b8c2a7547ab
permissions -rw-r--r--
Axiom of choice, cardinality results, etc.
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(*  Title: 	ZF/AC.thy
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    ID:         $Id$
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    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   1994  University of Cambridge
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The Axiom of Choice
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This definition comes from Halmos (1960), page 59.
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*)
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AC = ZF + "func" +
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rules
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  AC	"[| a: A;  !!x. x:A ==> (EX y. y:B(x)) |] ==> EX z. z : Pi(A,B)"
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end