Results 121 to 130 of about 166 (145)

Unification in varieties of completely regular semigroups

1992
All varieties of idempotent semigroups have been classified with respect to the unification types of their defining sets of identities. With the exception of eight finitary unifying theories, they are all of unification type zero. This yields countably many examples of theories of this type which are more “natural” than the first example constructed by
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Ladders and canonical varieties of completely regular semigroups

Periodica Mathematica Hungarica, 2017
The lattice \({\mathcal L} (\mathcal{CR})\) of varieties of completely regular semigroups contains as an ideal the well-studied lattice \({\mathcal{L}} (\mathcal{B})\) of bands. Two associated complete congruences are defined on \({\mathcal L} (\mathcal{CR})\): \(\mathcal{U} \mathrel{\mathbb{B}^{\wedge}} \mathcal{V}\) if \(\mathcal{U} \cap \mathcal{B} =
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Compactness of systems of equations on completely regular semigroups

1997
A semigroup S is said to have the compactness property, or CP for short, if each system of equations over a finite set of variables has an equivalent finite subsystem, that is, having exactly the same solutions in S. We prove that a completely 0-simple semigroup S satisfies CP if and only if the group G in a Rees matrix representation $S = {\mathcal M}^
Tero Harju, Juhani Karhumäki, Mario Petrich   +2 more
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Certain Varieties and Quasivarieties of Completely Regular Semigroups

Canadian Journal of Mathematics, 1977
We adopt the following definition of acompletely regular semigroup S:for every elementaofS,there exists a unique elementa-1ofSsuch ...
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New operators for varieties of completely regular semigroups

Semigroup Forum, 2015
In a series of articles, starting with [J. Aust. Math. Soc. 83, No. 1, 87-104 (2007; Zbl 1142.20035)], the author has investigated the decomposition of the lattice of varieties of completely regular semigroups induced by intersecting with the variety \(\mathbf B\) of bands.
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Completely regular and orthodox congruences on regular semigroups

1993
Let \(\rho\) be a congruence relation on a regular semigroup \(S\). Define \(\rho^ K\) [resp. \(\rho^ V\)] to be the greatest congruence relation on \(S\) such that the idempotent \((\rho^ K /\rho)\)-classes [resp. \((\rho^ V/ \rho)\)-classes] are bands [resp. rectangular bands].
Alimpić, Branka P., Krgović, Dragica N.   +1 more
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Completely Regular Semigroup

2004
Alain Connes, Bernard de Wit, Antoine Van Proeyen, Sergey Gukov, Rafael Hernandez, Pablo Mora, Anatoli Klimyk, Anatoli Klimyk, Iver Brevik, Alexander Gavrilik, Martin Schlichenmaier, Władysław Marcinek, Andrei Kelarev, Mikhail Shifman, Massimo Bianchi, Dimitry Leites, Rolf Schimmrigk, Pablo Mora, José de Azcarraga, José Izquierdo, Victor Rivelles, Stephan Narison, Masud Chaichian, Wenfeng Chen, Silvia Penati, Dimitry Leites, Roberto Floreanini, Anatoli Klimyk, Fang Li, Peter Trotter, Robert Marnelius, Steven Duplij, Władysław Marcinek, Steven Duplij, Władysław Marcinek, Władysław Marcinek, Warren Siegel, Fang Li, Peter Trotter   +38 more
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Completely regular semigroups

Semigroup Forum, 2001
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Certain relations on the congruence lattice of a completely regular semigroup

Semigroup Forum, 2014
Petrich Mario
exaly  

Residual finiteness in completely regular semigroup varieties

Semigroup Forum, 1988
P G Trotter
exaly