src/ZF/Ordinal.thy
author lcp
Thu Jan 12 03:01:40 1995 +0100 (1995-01-12)
changeset 852 664052e3cf66
parent 753 ec86863e87c8
child 1401 0c439768f45c
permissions -rw-r--r--
Now depends upon Bool, so that 1 and 2 are defined
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(*  Title: 	ZF/Ordinal.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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Ordinals in Zermelo-Fraenkel Set Theory 
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*)
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Ordinal = WF + Bool + "simpdata" + "equalities" +
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consts
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  Memrel      	:: "i=>i"
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  Transset,Ord  :: "i=>o"
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  "<"           :: "[i,i] => o"  (infixl 50) (*less than on ordinals*)
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  "le"          :: "[i,i] => o"  (infixl 50) (*less than or equals*)
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  Limit         :: "i=>o"
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translations
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  "x le y"      == "x < succ(y)"
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defs
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  Memrel_def  	"Memrel(A)   == {z: A*A . EX x y. z=<x,y> & x:y }"
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  Transset_def	"Transset(i) == ALL x:i. x<=i"
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  Ord_def     	"Ord(i)      == Transset(i) & (ALL x:i. Transset(x))"
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  lt_def        "i<j         == i:j & Ord(j)"
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  Limit_def     "Limit(i)    == Ord(i) & 0<i & (ALL y. y<i --> succ(y)<i)"
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end