From: Peter Freyd <pjf@saul.cis.upenn.edu>
To: categories@mta.ca
Subject: Re: connected categories and epimorphisms.
Date: Sun, 18 May 2003 14:19:19 -0400 (EDT) [thread overview]
Message-ID: <200305181819.h4IIJIgU022776@saul.cis.upenn.edu> (raw)
The quickest natural example I know of a connected category in which
projections from products needn't be epi is the category of
commutative rings. Well, actually, the opposite category. The
coproduct of Z_2 and Z_3 is the terminal ring. The two
co-projections fail to be monic (the coproduct of a pair of objects in
this category is their tensor product).
next reply other threads:[~2003-05-18 18:19 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-18 18:19 Peter Freyd [this message]
2003-05-20 9:13 ` Nikita Danilov
-- strict thread matches above, loose matches on Subject: below --
2003-05-16 19:41 Flavio Leonardo Cavalcanti de Moura
2003-05-18 17:45 ` Robin Cockett
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