From: Michael Barr <barr@math.mcgill.ca>
To: Categories list <categories@mta.ca>
Subject: Question on choosing subobjects consistently
Date: Thu, 26 Aug 2010 18:09:20 -0400 (EDT) [thread overview]
Message-ID: <E1Op3JD-0000DR-A3@mlist.mta.ca> (raw)
In his Tohoku paper, Grothendieck asserted with no proof that in any
category it is possible to choose subobjects for each object so that each
monomorphism is isomorphic to a unique subobject of the codomain and in
such a way that a subobject of a subobject of an object is also one of the
chosen subobjects of the original objects. Maybe I am being dense, but I
don't see how this is always possible. Does anyone on the list? I also
don't see what possible value there is in making such a choice, but this
doubtless was not clear in 1957.
The translation (and revision) is coming along fine and I expect to
release it within a month.
Michael
[For admin and other information see: http://www.mta.ca/~cat-dist/ ]
next reply other threads:[~2010-08-26 22:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-26 22:09 Michael Barr [this message]
2010-08-28 10:10 ` John Kennison
2010-08-28 12:24 Peter Freyd
2010-08-28 14:35 ` John Kennison
2010-08-29 13:32 ` Michael Barr
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