Results 1 to 10 of about 89 (75)

Idempotent 2x2 matrices over linearly ordered abelian groups [PDF]

Categories and General Algebraic Structures with Applications
In this paper we study multiplicative semigroups of $2\times 2$ matrices over a linearly ordered abelian group with an externally added bottom element. The multiplication of such a semigroup is defined by replacing addition and multiplication by join and
Valdis Laan, Marilyn Kutti
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Invariant semigroups of orthodox semigroups

Semigroup Forum, 1996
The paper is a continuation of a previous one of these authors [J. Algebra 169, No. 1, 49-70 (1994; Zbl 0811.06015)]. An inverse transversal of a regular semigroup \(S\) is an inverse subsemigroup \(T\) with the property that, for every \(x\in S\), \(T\) contains one and only one inverse element \(x^0\) of \(x\) in \(S\).
Blyth, T.S., Almeida-Santos, M.H.
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On generalized Ehresmann semigroups

Open Mathematics, 2017
As a generalization of the class of inverse semigroups, the class of Ehresmann semigroups is introduced by Lawson and investigated by many authors extensively in the literature.
Wang Shoufeng
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Certain congruences on orthodox semigroups [PDF]

Pacific Journal of Mathematics, 1976
Let \(S\) be a regular semigroup and \(E\) be the set of all its idempotents. The semigroup \(S\) is called unitary semigroup if \(e,ea\in E\) implies \(a\in E\) for all \(a,e\in S\). Regular semigroups are described which are underdirect products of unitary semigroups and semilattices of groups.
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Ordered Regular Semigroups with Biggest Associates

Discussiones Mathematicae - General Algebra and Applications, 2019
We investigate the class BA of ordered regular semigroups in which each element has a biggest associate x† = max {y | xyx = x}. This class properly contains the class PO of principally ordered regular semigroups (in which there exists x⋆ = max {y | xyx ...
Blyth T.S., Santos M.H. Almeida
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The isomorphism problem for orthodox semigroups [PDF]

Pacific Journal of Mathematics, 1989
The author's structure theorem for orthodox semigroups [ibid. 39, 677-686 (1971; Zbl 0232.20124)] produced an orthodox semigroup \({\mathcal H}(E,T,\psi)\) from a band \(E\), an inverse semigroup \(T\) and a morphism \(\psi\) between two inverse semigroups, namely \(T\) and \(W_ E/\gamma\), an inverse semigroup constructed from \(E\).
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Amenable Orders on Orthodox Semigroups

Journal of Algebra, 1994
From the authors' introduction. ``Let \(S\) be a semigroup. An inverse transversal of a regular semigroup \(S\) is an inverse subsemigroup \(T\) with the property \(| T\cap V(x)|=1\) for every \(x\in S\), where \(V(x)\) denotes the set of inverses of \(x\in S\). We write the unique element of \(T\cap V(x)\) as \(x^ 0\), and \(T\) as \(S^ 0= \{x^ 0\): \(
Blyth, T.S., Santos, M.H.A.
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On quasi-F-orthodox semigroups [PDF]

Proceedings of the Edinburgh Mathematical Society, 1995
An orthodox semigroup S is termed quasi-F-orthodox if the greatest inverse semigroup homomorphic image of S1 is F-inverse. In this paper we show that each quasi-F-orthodox semigroup is embeddable into a semidirect product of a band by a group. Furthermore, we present a subclass in the class of quasi-F-orthodox semigroups whose members S are embeddable ...
Billhardt, Bernd, Szendrei, Mária B.
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On lattice isomorphisms of orthodox semigroups [PDF]

Acta Scientiarum Mathematicarum, 2021
11 ...
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Elementary orthodox semigroups

Semigroup Forum, 1984
A semigroup is said to be elementary if it is generated by a subset \(A\cup B\) where \(aba=a\) and \(bab=b\) for all \(a\in A\), \(b\in B\). The authors extend their earlier work [Semigroup Forum 15, 295-309 (1978; Zbl 0403.20040)], in which free elementary orthodox semigroups were defined and their existence established, by studying the free ...
Williams, W., Eberhart, Carl
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