Abstract : We investigate the class of quasitrivial semigroups and provide various characterizations of the subclass of quasitrivial and commutative semigroups as well as the subclass of quasitrivial and order-preserving semigroups. We also determine explicitly the sizes of these classes when the semigroups are defined on finite sets. As a byproduct of these enumerations, we obtain several new integer sequences.
https://hal.inria.fr/hal-01826868
Contributor : Miguel Couceiro
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Submitted on : Monday, July 2, 2018 - 3:53:23 PM
Last modification on : Friday, May 10, 2019 - 11:35:57 PM
Long-term archiving on : Monday, October 1, 2018 - 9:37:18 AM
