English

Combinatorial results for certain semigroups of order-decreasing partial isometries of a finite chain

Group Theory 2017-02-16 v1

Abstract

Let In{\cal I}_n be the symmetric inverse semigroup on Xn={1,2,,n}X_n = \{1, 2, \ldots , n\} and let DDPn{\cal DDP}_n and ODDPn{\cal ODDP}_n be its subsemigroups of order-decreasing partial isometries and of order-preserving and order-decreasing partial isometries of XnX_n, respectively. In this paper we investigate the cardinalities of some equivalences on DDPn{\cal DDP}_n and ODDPn{\cal ODDP}_n which lead naturally to obtaining the order of the semigroups

Keywords

Cite

@article{arxiv.1702.04485,
  title  = {Combinatorial results for certain semigroups of order-decreasing partial isometries of a finite chain},
  author = {F. Al-Kharousi and R. Kehinde and A. Umar},
  journal= {arXiv preprint arXiv:1702.04485},
  year   = {2017}
}

Comments

14 pages, 2 tables