From: Paul Levy <pbl@cs.bham.ac.uk>
To: David Leduc <david.leduc6@googlemail.com>
Cc: categories <categories@mta.ca>
Subject: Re: Freyd Categories
Date: Sat, 25 Sep 2010 20:27:29 +0100 [thread overview]
Message-ID: <E1OzckT-0000aR-CL@mlist.mta.ca> (raw)
In-Reply-To: <E1Oz9g8-0003nH-U0@mlist.mta.ca>
On 23 Sep 2010, at 12:01, David Leduc wrote:
> A Freyd category is essentially a functor.
That's right. It's neither a category nor due to Freyd.
> So why is it called a category?!
I think there were two reasons.
Firstly to portray the category of computations as being more
important than the category of values.
Secondly because an identity-on-objects functor between two categories
with the same objects can be regarded as an [ -> , Set ] enriched
category. Here -> is the category with two objects and a morphism
between them (and identities). This point is emphasized in John
Power's paper "Premonoidal categories as categories with algebraic
structure" in TCS in 2002.
Paul
--
Paul Blain Levy
School of Computer Science, University of Birmingham
+44 (0)121 414 4792
http://www.cs.bham.ac.uk/~pbl
[For admin and other information see: http://www.mta.ca/~cat-dist/ ]
next prev parent reply other threads:[~2010-09-25 19:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-23 11:01 David Leduc
2010-09-25 19:27 ` Paul Levy [this message]
2010-09-25 21:48 ` Toby Bartels
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