src/ZF/Epsilon.thy
author clasohm
Thu Sep 16 12:20:38 1993 +0200 (1993-09-16)
changeset 0 a5a9c433f639
child 124 858ab9a9b047
permissions -rw-r--r--
Initial revision
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(*  Title: 	ZF/epsilon.thy
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    ID:         $Id$
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    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   1993  University of Cambridge
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Epsilon induction and recursion
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*)
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Epsilon = Nat +
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consts
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    eclose,rank ::      "i=>i"
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    transrec    ::      "[i, [i,i]=>i] =>i"
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rules
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  eclose_def	"eclose(A) == UN n:nat. nat_rec(n, A, %m r. Union(r))"
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  transrec_def	"transrec(a,H) == wfrec(Memrel(eclose({a})), a, H)"
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  rank_def    	"rank(a) == transrec(a, %x f. UN y:x. succ(f`y))"
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end