English

Discrete equational theories

Category Theory 2025-01-14 v4

Abstract

We introduce discrete equational theories where operations are induced by those having discrete arities. We characterize the corresponding monads as monads preserving surjections. Using it, we prove Birkhoff type theorems for categories of algebras of discrete theories. This extends known results from metric spaces to general symmetric monoidal closed categories.

Keywords

Cite

@article{arxiv.2204.02590,
  title  = {Discrete equational theories},
  author = {Jiří Rosický},
  journal= {arXiv preprint arXiv:2204.02590},
  year   = {2025}
}

Comments

an updated and corrected version, 17 pages

R2 v1 2026-06-24T10:39:22.308Z