From: Toby Bartels <categories@TobyBartels.name>
To: Categories <categories@mta.ca>
Subject: Re: Terminology: Remarks
Date: Wed, 1 May 2013 23:46:54 -0700 [thread overview]
Message-ID: <E1UY2m4-0008Ed-Pm@mlist.mta.ca> (raw)
In-Reply-To: <BD80E582-7ABD-44B4-8B8D-218AD7C47720@wanadoo.fr>
Jean B?nabou wrote in small part:
>The one [notion of equivalence of categories] which might serve here is f
>full and faithful and essentially surjective. But unless we have AC it is
>not symmetric, even for A and B small.
Then the obvious thing to try is to symmetrise it:
An equivalence between A and B is a span A <- X -> B
of fully faithful and essentially surjective functors.
--Toby
[For admin and other information see: http://www.mta.ca/~cat-dist/ ]
next prev parent reply other threads:[~2013-05-02 6:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-01 5:17 Jean Bénabou
2013-05-02 6:46 ` Toby Bartels [this message]
2013-05-02 23:47 ` Tom Leinster
2013-05-03 1:41 ` Eduardo J. Dubuc
2013-05-03 4:53 ` Jean Bénabou
[not found] ` <16016_1367583941_5183ACC5_16016_35_1_E1UYF2N-0003Ot-Lk@mlist.mta.ca>
2013-05-03 23:22 ` Marta Bunge
2013-05-03 15:07 ` Marta Bunge
2013-05-04 5:34 ` Toby Bartels
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