3 Jul
1998
3 Jul
'98
2:10 a.m.
The paper "Exponentiablity and Single Universes" by Marta Bunge and Susan Niefield, recently announced on the site ww1.union.edu/~niefiels has been temporarily withdrawn. A revised version will be posted soon. The paper contained an erroneous result - namely, that for an arbitrary small category B, the category UFL/B of Giraud-Conduche fibrations over B is a topos. A counterexample has been found by Peter Johnstone.