Re: Non-standard models of PA

Chris Menzel says...
>
>On 29 Aug 2005 06:08:32 -0700, Daryl McC <stevendaryl3016@xxxxxxxxx> said:

>> As I understand it, there is a countable model of the integers (positive
>> and negative whole numbers) that has the following character:
>>
>> *Z (the nonstandard model of the integers)
>> is isomorphic to QxZ, where Q is the nonnegative
>> rationals, ...
>
>IIRC, the structure of the copies of the integers in any nonstandard
>model of PA has to be dense linear order w.o. endpoints.

You're right. So Q should be the full rationals (positive, negative,
and zero).

--
Daryl McCullough
Ithaca, NY

.

Quantcast