Internal categories, anafunctors and localisations
arXiv:1101.2363
Abstract
In this article we review the theory of anafunctors introduced by Makkai and Bartels, and show that given a subcanonical site S, one can form a bicategorical localisation of various 2-categories of internal categories or groupoids at weak equivalences using anafunctors as 1-arrows. This unifies a number of proofs throughout the literature, using the fewest assumptions possible on S.
42 pages. Final version to appear in Theory and Applications of Categories. License is CC-BY
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- On fibrations between internal groupoids
- The derivator of setoids
- Butterflies in a Semi-Abelian Context