Results 71 to 80 of about 543 (107)

On orthodox P-restriction semigroups

Journal of Algebra and Its Applications, 2021
The investigation of orthodox [Formula: see text]-restriction semigroups was initiated by Jones in 2014 as generalizations of orthodox [Formula: see text]-semigroups. The aim of this paper is to further study orthodox [Formula: see text]-restriction semigroups based on the known results of Jones. After establishing a construction theorem for orthodox [
Wang, Shoufeng, Shum, K. P.
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Formations of orthodox semigroups

Semigroup Forum, 2023
A semigroup \(S\) is said to be \textit{regular} if for each \(a\in S\) there is \(b\in S\) with \(aba = a\). An \textit{orthodox semigroup} is a regular semigroup whose set of idempotents is a subsemigroup. A class of orthodox semigroups is called a \textit{bivariety} if it is closed for orthodox subsemigroups, for quotients, and for direct products ...
Gomes, Gracinda M. S.   +1 more
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On U-orthodox semigroups

Science in China Series A: Mathematics, 2009
Let \(S\) be a semigroup with the set of idempotents \(E(S)\). For \(a\in S\) and a non-empty subset \(U\subseteq E(S)\) denote \(U_a^r=\{u\in U\mid au=a\}\) and define relation \(\widetilde{\mathcal L}^U\) by \(a\widetilde{\mathcal L}^Ub\Leftrightarrow U_a^r=U_b^r \); definition of \(\widetilde{\mathcal R}^U\) is dual.
Ren, Xue-Ming   +2 more
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Isbell’s Zigzag theorem for permutative orthodox semigroups and clifford semigroups

Asian-European Journal of Mathematics, 2021
In this paper, we prove that the dominion of any full orthodox subsemigroup of a medial orthodox semigroup is described by the Isbell zigzag theorem in the category of medial orthodox semigroups. As a consequence, the dominions of any full completely regular subsemigroup of a medial completely regular semigroup as well as that of any full Clifford ...
Noor Alam, Noor Mohammad Khan
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ORTHODOX TRANSVERSALS OF REGULAR SEMIGROUPS

International Journal of Algebra and Computation, 2001
Orthodox transversals were introduced by the first author as a generalization of inverse transversals [Comm. Algebra 27(9) (1999), pp. 4275–4288]. One of our aims in this note is to consider the general case of orthodox transversals. The main results are on the sets I and Λ, two components of regular semigroups with orthodox transversals.
Chen, J. F., Cuo, Y. Q.
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Weakly $$B$$ B -orthodox semigroups

Periodica Mathematica Hungarica, 2014
In the introduction the author has written that ``the article [J. Algebra 368, 209-230 (2012; Zbl 1275.20067)] by \textit{V. Gould} and \textit{Y. Wang} is the first of three in which we investigate the correspondence between algebraic structures and ordered categories, in the sense of Ehresmann-Schein-Nambooripad\dots.
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Congruences on orthodox semigroups II

Journal of the Australian Mathematical Society, 1972
If ρ is a congruence on a regular semigroup S, then the kernel of ρ is defined to be the set of ρ-classes which contain idempotents of S. Preston [7] has proved that two congruences on a regular semigroup coincide if and only if they have the same kernel: this naturally poses the problem of characterizing the kernel of a congruence on a regular ...
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STANDARD REPRESENTATIONS OF ORTHODOX SEMIGROUPS

Communications in Algebra, 2005
Abstract Orthodox semigroups have been studied by many authors, in particular by Hall, Yamada and Petrich. In this paper, we give the standard representation of orthodox semigroups and investigate various e-varieties of orthodox semigroups which are determined by the standard representations.
Yong He, Yuqi Guo, K.P. Shum
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Almost Factorizable Orthodox Semigroups

Semigroup Forum, 2006
In this paper, we investigate idempotent separating and arbitrary homomorphic images of semidirect products of bands by groups. We give characterizations for idempotent separating homomorphic images of semidirect products, and show that the class of all idempotent separating homomorphic images is strictly contained in the class of all homomorphic ...
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