A Note on Discrete Conduché Fibrations
نویسنده
چکیده
The class of functors known as discrete Conduché fibrations forms a common generalization of discrete fibrations and discrete opfibrations, and shares many of the formal properties of these two classes. F. Lamarche [7] conjectured that, for any small category B, the category DCF/B of discrete Conduché fibrations over B should be a topos. In this note we show that, although for suitable categories B the discrete Conduché fibrations over B may be presented as the ‘sheaves’ for a family of coverings on a category Btw constructed from B, they are in general very far from forming a topos.
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تاریخ انتشار 2001