9 Oct
2006
9 Oct
'06
1:37 p.m.
On Mon, 9 Oct 2006, Richard Garner wrote:
Dear categorists,
I have a proof that the indiscrete category functor Set -> Cat preserves reflexive coequalizers which, although straightfoward, uses the explicit description of colimits in Cat. Is this necessary, or can I deduce the result from general principles?
It certainly follows from the fact that reflexive coequalizers commute with finite products in Set (or in any cartesian closed category). This is a result that some people attribute to me, since the first place it was explicitly written down seems to have been my PhD thesis, though I'm sure it was known well before that. Peter Johnstone