De Morgan's law in toposes I
Category Theory
2026-04-29 v2 Logic
Abstract
We study toposes satisfying De Morgan's law, in particular we give characterizations of geometric theories whose classifying topos is De Morgan, clarifying the link with the amalgamation property of the category of models of such theory. We then give several ways of turning a topos into a De Morgan topos.
Keywords
Cite
@article{arxiv.2507.01869,
title = {De Morgan's law in toposes I},
author = {Olivia Caramello and Yorgo Chamoun},
journal= {arXiv preprint arXiv:2507.01869},
year = {2026}
}
Comments
53 pages