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arXiv · 1702.04485

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

F. Al-Kharousi·R. Kehinde·A. Umar
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Abstract

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

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F. Al-Kharousi, R. Kehinde, A. Umar. 2017-02-15. Combinatorial results for certain semigroups of order-decreasing partial isometries of a finite chain. https://arxiv.org/abs/1702.04485

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