From: "Fred E.J. Linton" <fejlinton@usa.net>
To: <categories@mta.ca>
Subject: Re: A small cartesian closed concrete category
Date: Thu, 14 Feb 2008 22:46:44 -0500 [thread overview]
Message-ID: <E1JQ1hV-0006Xq-7n@mailserv.mta.ca> (raw)
On Thu, 14 Feb 2008 10:07:27 PM EST, PETER EASTHOPE <peasthope@shaw.ca>
asked:
> Is there a cartesian closed concrete category which
> is small enough to write out explicitly?
How about the full category of finite sets? Or,
if that's not small enough, and you really fancy an example
> ... made with binary numbers for instance ,
try the skeletal version of the full category of "sets of cardinality < 2"
having as only objects the ordinal numbers 0 and 1.
Here 0 x A = 0, 1 x A = A, 0^1 = 0, 0^0 = 1, 1^A = 1.
In other words, B x A = min(A, B), B^A = max(1-A, B).
Happy Valentines's Day! -- Fred
next reply other threads:[~2008-02-15 3:46 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-15 3:46 Fred E.J. Linton [this message]
-- strict thread matches above, loose matches on Subject: below --
2008-05-25 15:50 Fred E.J. Linton
2008-05-22 16:27 PETER EASTHOPE
2008-05-16 20:57 Toby Bartels
2008-03-03 21:30 wlawvere
2008-03-03 14:37 peasthope
2008-02-16 12:21 Thorsten Altenkirch
2008-02-16 1:51 Colin McLarty
2008-02-16 0:17 Andrej Bauer
2008-02-15 19:08 Matt Hellige
2008-02-15 8:18 Paul Taylor
2008-02-14 20:06 PETER EASTHOPE
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