From: Joachim Kock <kock@mat.uab.cat>
To: Peter Selinger <selinger@mathstat.dal.ca>,
Categories List <categories@mta.ca>
Subject: Re: opposite category
Date: Fri, 15 Sep 2017 20:23:19 +0200 [thread overview]
Message-ID: <E1dtI50-0000SS-P6@mlist.mta.ca> (raw)
In-Reply-To: <E1dsucr-0002B6-7j@mlist.mta.ca>
On 14/09/2017 17:58, Peter Selinger wrote:
> Robert Pare wrote:
>>
>> He said there may come a time when we have to consider covariant
>> functors as contravariant ones on the opposite category.
Indeed: Segal's (1974) Gamma-spaces are contravariant
functors on the opposite of the category of finite pointed
sets.
Joachim.
[For admin and other information see: http://www.mta.ca/~cat-dist/ ]
next prev parent reply other threads:[~2017-09-15 18:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1EE29452-3443-447D-BCDE-0A76B4F0562D@dal.ca>
2017-09-06 16:51 ` Fred Robert Pare
2017-09-07 0:42 ` Fred Ross Street
2017-09-14 15:58 ` opposite category Peter Selinger
2017-09-15 18:23 ` Joachim Kock [this message]
2017-09-16 1:20 ` Vaughan Pratt
2017-09-16 15:44 ` Joyal, André
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