6 Mar
2015
6 Mar
'15
2:28 a.m.
[Note from moderator: Many responses to this; will forward the first mentioning each source. Thanks to other posters. ] On 5 March 2015 at 11:49, Uwe Egbert Wolter <Uwe.Wolter@ii.uib.no> wrote:
Some years ago (around 30?)
25
I read a book where it was mentioned that one could define categories without (explicit) objects in the sense that objects are mimicked by identity morphisms. Unfortunately, I can not reconstruct what book it was.
I know how this works. I would, however, like to have a reference.
Peter J Freyd and Andre Scedrov, "Categories, Allegories" (Elsevier, 1990) ISBN 0 444 70368 3 is one such. Best wishes, Andy Pitts [For admin and other information see: http://www.mta.ca/~cat-dist/ ]