From: "Prof. Peter Johnstone" <P.T.Johnstone@dpmms.cam.ac.uk>
To: categories@mta.ca
Subject: Re: Reflexive coequalizers
Date: Mon, 9 Oct 2006 14:37:24 +0100 (BST) [thread overview]
Message-ID: <Pine.LNX.4.58.0610091433210.29643@siskin.dpmms.cam.ac.uk> (raw)
In-Reply-To: <E1GWuQU-0002KX-0S@mailserv.mta.ca>
On Mon, 9 Oct 2006, Richard Garner wrote:
>
> Dear categorists,
>
> I have a proof that the indiscrete category functor
> Set -> Cat preserves reflexive coequalizers which,
> although straightfoward, uses the explicit
> description of colimits in Cat. Is this necessary,
> or can I deduce the result from general
> principles?
>
It certainly follows from the fact that reflexive coequalizers
commute with finite products in Set (or in any cartesian closed
category). This is a result that some people attribute to me,
since the first place it was explicitly written down seems to
have been my PhD thesis, though I'm sure it was known well
before that.
Peter Johnstone
next prev parent reply other threads:[~2006-10-09 13:37 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-09 10:14 Richard Garner
2006-10-09 13:37 ` Prof. Peter Johnstone [this message]
2006-10-09 14:47 Jiri Adamek
2006-10-09 18:40 George Janelidze
2006-10-09 20:09 Richard Garner
2006-11-06 13:39 reflexive coequalizers Jiri Adamek
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