English

Finite semilattices with many congruences

Rings and Algebras 2018-01-08 v1 Combinatorics

Abstract

For an integer n2n\geq 2, let NCSL(n)(n) denote the set of sizes of congruence lattices of nn-element semilattices. We find the four largest numbers belonging to NCSL(n)(n), provided that nn is large enough to ensure that |NCSL(n)4(n)|\geq 4. Furthermore, we describe the nn-element semilattices witnessing these numbers.

Keywords

Cite

@article{arxiv.1801.01482,
  title  = {Finite semilattices with many congruences},
  author = {Gábor Czédli},
  journal= {arXiv preprint arXiv:1801.01482},
  year   = {2018}
}

Comments

14 pages, 4 figures

R2 v1 2026-06-22T23:36:42.413Z