Prior work towards the subject of higher-dimensional categories gives rise to several examples of a category over $Cat$ to which the slice-category construction can be lifted universally. The present paper starts by supplying this last clause with a precise meaning. It goes on to establish for any such category a certain embedding in a presheaf category, to describe the image, and hence to derive conditions collectively sufficient for that functor to be an equivalence. These conditions are met in the foremost of the examples: the category of dendrotopic sets.

Keywords: slice categories, presheaf category, polytopic sets

2000 MSC: 18D99

*Theory and Applications of Categories,*
Vol. 22, 2009,
No. 5, pp 97-135.

http://www.tac.mta.ca/tac/volumes/22/5/22-05.dvi

http://www.tac.mta.ca/tac/volumes/22/5/22-05.ps

http://www.tac.mta.ca/tac/volumes/22/5/22-05.pdf

ftp://ftp.tac.mta.ca/pub/tac/html/volumes/22/5/22-05.dvi

ftp://ftp.tac.mta.ca/pub/tac/html/volumes/22/5/22-05.ps