English

Extending the Ehresmann-Schein-Nambooripad Theorem

Rings and Algebras 2010-03-26 v3 Category Theory

Abstract

We extend the `join-premorphisms' part of the Ehresmann-Schein-Nambooripad Theorem to the case of two-sided restriction semigroups and inductive categories, following on from a result of Lawson (1991) for the `morphisms' part. However, it is so-called `meet-premorphisms' which have proved useful in recent years in the study of partial actions. We therefore obtain an Ehresmann-Schein-Nambooripad-type theorem for meet-premorphisms in the case of two-sided restriction semigroups and inductive categories. As a corollary, we obtain such a theorem in the inverse case.

Keywords

Cite

@article{arxiv.0804.4702,
  title  = {Extending the Ehresmann-Schein-Nambooripad Theorem},
  author = {Christopher Hollings},
  journal= {arXiv preprint arXiv:0804.4702},
  year   = {2010}
}

Comments

23 pages; final section on Szendrei expansions removed; further reordering of material

R2 v1 2026-06-21T10:35:48.718Z