Results 61 to 70 of about 93 (82)

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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ON E-UNITARY COVERS OF ORTHODOX SEMIGROUPS

International Journal of Algebra and Computation, 1993
In this paper we prove that each orthodox semigroup S has an E-unitary cover embeddable into a semidirect product of a band B by a group where B belongs to the band variety generated by the band of idempotents in S. This result is related to an embeddability question on E-unitary regular semigroups raised previously.
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STRONGLY ORTHODOX CONGRUENCES ON AN -INVERSIVE SEMIGROUP

Journal of the Australian Mathematical Society, 2013
AbstractIn this paper we investigate some subclasses of strongly regular congruences on an$E$-inversive semigroup$S$. We describe the minimum and the maximum strongly orthodox congruences on$S$whose characteristic trace coincides with the characteristic trace of given congruences and, in each case, we present an alternative characterization for them. A
Fan, Xingkui, Chen, Qianhua
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On Some Existence Varieties of Locally Orthodox Semigroups

International Journal of Algebra and Computation, 1997
The main objective of the paper is to study existence varieties generated by Mal'cev products of the form \({\mathcal P}({\mathcal Y})\circ{\mathcal Q}\) where \(\mathcal Q\) is an (e-)variety of completely simple semigroups not consisting entirely of rectangular groups and \(\mathcal P(\mathcal Y)\) is the (e-)variety of bands all of whose monoids ...
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On left quasinormal orthodox semigroups

Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 1983
SynopsisThe existence of a smallest inverse congruence on an orthodox semigroup is known. It is also known that a regular semigroupSis locally inverse and orthodox if and only if there exists a local isomorphism fromSonto an inverse semigroupT.In this paper, we show the existence of a smallestR-unipotent congruence ρ on an orthodox semigroupSand give ...
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\(\Gamma\)-orthodox semigroups

1994
Summary: The notion of \(\Gamma\)-semigroups was introduced by M. K. Sen and N. K. Saha in the year 1986, they also introduced the concept of orthodox \(\Gamma\)-semigroup in 1990. In this paper we introduce \(\Gamma\)-orthodox semigroups and \(\Gamma\)-regular semigroups and present some basic properties of these \(\Gamma\)-semigroups.
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Orthodox Congruences on An Eventually Regular Semigroup

Semigroup Forum, 2007
Yanfeng Luo, Luo Yanfeng
exaly  

On a pull-back diagram for orthodox semigroups

Semigroup Forum, 1980
Maria Szendrei
exaly  

Orthodox semigroups and permutation matchings

Semigroup Forum, 2016
Higgins Peter M
exaly  

E-unitary almost factorizable orthodox semigroups

Semigroup Forum, 2011
Maria Szendrei, Szendrei Maria B
exaly