On Thu, Nov 9, 2017 at 3:26 AM, Andrée Ehresmann <andree.ehresmann@u-picardie.fr> wrote:
I have been surprised to see the definition given in nLab of a sketch as a category with some limit-cones and co-limit-cones. For us, a 'sketch' is a category S (or even a graph) with some distinguished cones and co-cones (but not necessarily (co-)limit-cones).
Thanks for pointing this out. I think this is an error on the nLab page, or perhaps a sloppy phrasing that got misinterpreted by a later editor; I'll fix it. In the case when a sketch is a graph rather than a category, it has to come equipped also with some distinguished diagrams that are supposed to commute in its models, right? [For admin and other information see: http://www.mta.ca/~cat-dist/ ]