* Re: Combining monads and Pullback cats
@ 1998-01-20 21:33 categories
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From: categories @ 1998-01-20 21:33 UTC (permalink / raw)
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Date: Tue, 20 Jan 98 15:30:07 EST
From: John Duskin <duskin@math.buffalo.edu>
Mike is right. The problem lies in the existence of a left adjoint. However
if one pulls back over a Grothendieck co-(=op-)fibration, then if U has a
left adjoint, then so does its pullback. In fact, a functor is a
cofibration iff it is universal for this property, i.e., it has this
property and this property is stable under arbitrary pullbacks."A
cofibration is a universal change of base for right adjoints". I don't know
if this is of much help, but it is amusing.
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1998-01-20 21:33 Combining monads and Pullback cats categories
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