From: "René Guitart" <rene.guitart@orange.fr>
To: Uwe Egbert Wolter <Uwe.Wolter@ii.uib.no>
Cc: categories@mta.ca
Subject: Re: Category without objects
Date: Thu, 5 Mar 2015 19:55:42 +0100 [thread overview]
Message-ID: <E1YTs4F-0005D0-08@mlist.mta.ca> (raw)
In-Reply-To: <E1YTXbm-00060C-69@mlist.mta.ca>
In fact this point is observed even in the original paper of Eilenberg Mac Lane !
Furthermore, I recently proposed a notion of autocategory, a kind of category without object ; this is a little different from categories, and is based precisely on the distinction between four things : objects, identities, identifiers, domains or codomains (see in CTGD in 2014), and this allows to see with the same "eye" categories, 2-categories, etc..
Best,
René Guitart
Le 5 mars 2015 à 12:49, Uwe Egbert Wolter a écrit :
> Some years ago (around 30?) I read a book where it was mentioned that
> one could define categories without (explicit) objects in the sense that
> objects are mimicked by identity morphisms. Unfortunately, I can not
> reconstruct what book it was.
>
> I know how this works. I would, however, like to have a reference.
>
> Best
>
> Uwe Wolter
>
[For admin and other information see: http://www.mta.ca/~cat-dist/ ]
prev parent reply other threads:[~2015-03-05 18:55 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-05 11:49 Uwe Egbert Wolter
2015-03-05 15:28 ` Andrew Pitts
2015-03-05 16:49 ` Jiri Adamek
2015-03-05 19:14 ` Eduardo J. Dubuc
2015-03-05 23:45 ` Peter LeFanu Lumsdaine
[not found] ` <CAAkwb-=thVBruC0prBLKOjPkhZaCjgA030vgfYw0de7c_MQm3w@mail.gmail.com>
2015-03-06 14:42 ` Uwe Egbert Wolter
2015-03-07 14:36 ` Ronnie Brown
2015-03-08 16:44 ` Eduardo J. Dubuc
2015-03-08 19:53 ` F. William Lawvere
[not found] ` <SNT153-W699E615B487A28AE1166E8C61A0@phx.gbl>
2015-03-08 22:51 ` Ronnie Brown
2015-03-11 4:20 ` Vaughan Pratt
2015-03-12 0:42 ` Tadeusz Litak
2015-03-15 15:34 ` Eduardo J. Dubuc
2015-03-05 18:55 ` René Guitart [this message]
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