Article View: sci.logic
Article #214Re: Non-standard integers.
From: Bill Taylor
Date: Wed, 19 Aug 1992 05:29
Date: Wed, 19 Aug 1992 05:29
23 lines
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1744 bytes
> 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 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> Distribution: world Organization: Department of Mathematics, University of Canterbury Nntp-Posting-Host: math.canterbury.ac.nz Lines: 23