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Article #214

Re: Non-standard integers.

#214
From: Bill Taylor
Date: Wed, 19 Aug 1992 05:29
23 lines
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>	Kemeny's conjecture is false: If M is a non-standard model of
>PA, then there is a non-standard integer n such that no integer in the
>"standard row" of n is divisible by all standard integers.
>
>	To see this, take n which is odd but is divisible by all
>standard odd integers. If m differs from n by a standard integer, then
>there must be a standard odd prime which does not divide the
>difference. Hence m is not divisible by that prime.

Looking at this bit...

>take n which is odd but is divisible by all standard odd integers.

...at first it wasn't clear to me that every nonstandard model would have
such an  n .  But I suppose this can be seen by taking any odd nonstandard k,
and forming  n = k(k-2)(k-4)(k-6).....  .

Presumably this operation can be made legitimate in some simple way ?
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            Bill Taylor              wft@math.canterbury.ac.nz 
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                  Kleeneness is next to Godelness.
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Path: arc1-ca.pugleaf.net!sparky!uunet!wupost!waikato.ac.nz!canterbury.ac.nz!math!wft
References: <1992Aug17.141017.373@csc.canterbury.ac.nz> <16npkvINNjlq@agate.berkeley.edu> <1992Aug18.133344.385@csc.canterbury.ac.nz> <16rh2nINN6og@agate.berkeley.edu>

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Path: arc1-ca.pugleaf.net!sparky!uunet!wupost!waikato.ac.nz!canterbury.ac.nz!math!wft
Newsgroups: sci.logic
Subject: Re: Non-standard integers.
Message-ID: <1992Aug19.172922.410@csc.canterbury.ac.nz>
From: wft@math.canterbury.ac.nz (Bill Taylor)
Date: 19 Aug 92 17:29:20 +1200
References: <1992Aug17.141017.373@csc.canterbury.ac.nz> <16npkvINNjlq@agate.berkeley.edu> 
 <1992Aug18.133344.385@csc.canterbury.ac.nz> <16rh2nINN6og@agate.berkeley.edu>
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