On the theories classified by an \'etendue
Logic
2025-12-30 v3 Category Theory
Abstract
We give a model-theoretic characterisation of the geometric theories classified by \'etendues -- the `locally localic' topoi. They are the theories where each model is determined, syntactically and semantically, by any witness of a fixed collection of formulae.
Keywords
Cite
@article{arxiv.2507.04526,
title = {On the theories classified by an \'etendue},
author = {Joshua Wrigley},
journal= {arXiv preprint arXiv:2507.04526},
year = {2025}
}
Comments
Substantial changes, fixing an error in the previous version. 19 pages