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From: Thorsten Altenkirch <txa@Cs.Nott.AC.UK>
To: Ondrej Rypacek <ondrej.rypacek@gmail.com>
Cc: categories@mta.ca
Subject: Re: colimits of polynomial functors
Date: Tue, 1 Feb 2011 11:47:14 +0000	[thread overview]
Message-ID: <E1PkdQV-0005qx-Ii@mlist.mta.ca> (raw)
In-Reply-To: <E1PjxtH-000495-PM@mlist.mta.ca>


On 31 Jan 2011, at 15:13, Ondrej Rypacek wrote:

> Dear all
> 
> Does the category of (dependent) polynomial functors and strong
> natural transformation have all/some colimits ?
> In general, what is known about them ?
> 
> Many thanks!
> Ondrej
> 
> 
> [For admin and other information see: http://www.mta.ca/~cat-dist/ ]


There are not closed under coequalizers, eg. we can obtained unordered pairs as the coequalizer of id,swap : AxA -> AxA where swao (x,y) = (y,x). To include those one has to move to (what we called) "quotient containers" generalizing analytical functors. 

Thorsten



[For admin and other information see: http://www.mta.ca/~cat-dist/ ]


  parent reply	other threads:[~2011-02-01 11:47 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-31 15:13 Ondrej Rypacek
2011-01-31 18:22 ` Paul Taylor
2011-02-01 11:47 ` Thorsten Altenkirch [this message]
2011-02-03 17:04 ` Marek Zawadowski
2011-02-01 23:34 Joachim Kock
2011-02-02 18:48 ` Joachim Kock

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