English

Closure algebras of depth two with extremal relations: Their frames, logics, and structural completeness

Logic 2023-09-21 v1

Abstract

We consider varieties generated by finite closure algebras whose canonical relations have two levels, and whose restriction to a level is an "extremal" relation, i.e. the identity or the universal relation. The corresponding logics have frames of depth two, in which a level consists of a set of simple clusters or of one cluster with one or more elements.

Keywords

Cite

@article{arxiv.2309.10946,
  title  = {Closure algebras of depth two with extremal relations: Their frames, logics, and structural completeness},
  author = {Ivo Düntsch and Wojciech Dzik},
  journal= {arXiv preprint arXiv:2309.10946},
  year   = {2023}
}
R2 v1 2026-06-28T12:26:40.573Z