From: burroni@math.jussieu.fr
To: "Joyal, André" <joyal.andre@uqam.ca>, categories@mta.ca
Subject: Re: to PTJ
Date: Sun, 15 Nov 2009 18:20:51 +0100 [thread overview]
Message-ID: <E1N9oHq-0003bA-9f@mailserv.mta.ca> (raw)
In-Reply-To: <E1N8cy4-00005d-Gt@mailserv.mta.ca>
Hi,
You can find this equation (and ref to Higman and Neumann) in the GTM
springer no 26 page 7 : E.G. manes "Algebraic Theory.
xxxdydzdxxdxdzddd=y
(polish notations and d is the binary operation.)
Best,
Albert
"Joyal, André" <joyal.andre@uqam.ca> a écrit :
> Hi Peter,
>
>> And, as someone (I forget who, but it may have been Mike Barr) pointed
>> out long ago, one can (well, almost) define the variety of groups
>> as the variety defined by a single binary operation satisfying a
>> single equation; 1 < 3, but no sane group-theorist would do it
>> that way.
>
> I recall that Tarski is responsible for describing
> the theory of groups with a single binary operation satisfying a
> single equation. But dont have a reference with me.
>
> A small point: the algebraic theory described by Tarski
> admits the empty set as a model. Strictly speaking,
> it is not equivalent to the theory of group.
>
> Best,
> André
>
>
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next prev parent reply other threads:[~2009-11-15 17:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-12 7:07 Lambek's lemma Vaughan Pratt
2009-11-12 20:31 ` Vaughan Pratt
2009-11-12 20:59 ` Charles Wells
2009-11-12 21:14 ` Prof. Peter Johnstone
2009-11-13 8:15 ` Vaughan Pratt
2009-11-13 21:49 ` Prof. Peter Johnstone
2009-11-14 19:37 ` to PTJ Joyal, André
2009-11-14 22:20 ` Lambek's lemma Vaughan Pratt
2009-11-13 10:07 ` Steve Vickers
2009-11-15 17:20 ` burroni [this message]
2009-11-16 11:25 ` to PTJ Ronnie Brown
2009-11-15 21:07 ` Andrej Bauer
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