English

Identities and bases in the hypoplactic monoid

Rings and Algebras 2021-07-14 v3 Combinatorics Group Theory

Abstract

This paper presents new results on the identities satisfied by the hypoplactic monoid. We show how to embed the hypoplactic monoid of any rank strictly greater than 2 (including infinite rank) into a direct product of copies of the hypoplactic monoid of rank 2. This confirms that all hypoplactic monoids of rank greater than or equal to 2 satisfy exactly the same identities. We then give a complete characterization of those identities, and prove that the variety generated by the hypoplactic monoid has finite axiomatic rank, by giving a finite basis for it.

Keywords

Cite

@article{arxiv.2010.06953,
  title  = {Identities and bases in the hypoplactic monoid},
  author = {Alan J. Cain and António Malheiro and Duarte Ribeiro},
  journal= {arXiv preprint arXiv:2010.06953},
  year   = {2021}
}

Comments

19 pages

R2 v1 2026-06-23T19:20:12.091Z