Subject: categories: preprint (revised) available

From: Jonathon Funk <[email-masked]>
Date: Wed, 9 Dec 1998 22:22:03 -0800 (PST)

The preprint: On Branched Covers in Topos Theory

is available from my home page

http://www.math.ubc.ca/~funk/

in postscript or .dvi format.

This is a revision and extension of a preprint I had
posted from Cyprus in June, 98.

Abstract: We present some new findings concerning branched covers in
topos theory. Our discussion involves a particular subtopos of a given
topos that can be described as the smallest subtopos closed under small
coproducts in the including topos.
Our main result is a description of the covers of this subtopos as a 
category of fractions of branched covers, in the sense of R. Fox, of the
including topos.  We also have some new results concerning the general
theory of KZ-doctrines, such as the closure under composition of discrete
fibrations for a KZ-doctrine, in the sense of Bunge-Funk.