Combinatorial results for certain semigroups of order-preserving full contraction mappings of a finite chain
| Autor: | Adeshola, A. D., Umar, A. |
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| Rok vydání: | 2013 |
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| Druh dokumentu: | Working Paper |
| Popis: | Let ${\cal T}_n$ be the full symmetric semigroup on $X_n = \{1, 2,..., n\}$ and let ${\cal OCT}_n$ and ${\cal ORCT}_n$ be its subsemigroups of order-preserving and order-preserving or order-reversing full contraction mappings of $X_n$, respectively. In this paper we investigate the cardinalities of some equivalences on ${\cal OCT}_n$ and ${\cal ORCT}_n$ which lead naturally to obtaining the orders of these subsemigroups. Comment: 11 pages. arXiv admin note: text overlap with arXiv:1101.0049 by other authors There are two authors now instead of the previous three |
| Databáze: | arXiv |
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