Results 11 to 20 of about 37 (22)

The existence of an associate subgroup in normal cryptogroups

Publicationes Mathematicae, 2008
Let \(S\) be a semigroup. If \(a=axa\) for \(a,x\in A\) then \(x\) is called an associate of \(a\). A subgroup \(G\) of \(S\) is an associate subgroup of \(S\) if it contains exactly one associate of each element of \(S\). Every maximal subgroup of a regular semigroup \(S\) is an associate subgroup if and only if \(S\) is completely simple, or ...
exaly   +2 more sources

Characterizing cryptogroups with a finite number of $${\mathcal{H}}$$ -classes in each $${\mathcal{D}}$$ -class by their subsemigroups

Annali Di Matematica Pura Ed Applicata, 2007
Mariio Petrich, Petrich Mario
exaly   +2 more sources

GREEN ♯-RELATIONS AND NORMAL ${\cal H}^\sharp$-CRYPTOGROUPS

Asian-European Journal of Mathematics, 2009
In this paper, a new set of generalized Green's relations on a semigroup S, namely the set of Green ♯-relations, are introduced. By using these new Green ♯-relations, we prove that an [Formula: see text]-abundant semigroup is a normal [Formula: see text]-cryptogroup if and only if it is a strong semilattice of completely [Formula: see text]-simple ...
Xiang-zhi Kong, K. P. Shum
openaire   +1 more source

Some Normal Cryptogroups as Semigroups of Isomorphisms

Results in Mathematics, 1996
A cryptogroup \(S\) is a completely regular semigroup in which the Green relation \(\mathcal H\) is a congruence, that is a band of groups. If, in addition, \(S/{\mathcal H}\) is a normal band, then \(S\) is a normal cryptogroup or a normal band of groups. A semilattice of groups \(G=[Y;G_\alpha,w_{\alpha,\beta}]\) is called a Clifford semigroup. Given
openaire   +2 more sources

Basis reduction for cryptogroups and orthogroups

Semigroup Forum, 2020
A C Casimiro, Eduardo Skapinakis
exaly  

On Malcev Products of Normal Cryptogroups

Results in Mathematics, 2014
Mariio Petrich, Petrich Mario
exaly  

A Lattice of Quasivarieties of Normal Cryptogroups

Semigroup Forum, 2007
Mariio Petrich, Petrich Mario
exaly  

Some Normal Cryptogroups as Semigroups of Isomorphisms

Resultate Der Mathematik, 2013
Petrich Mario
exaly  

Bands of groups with universal properties

Monatshefte Fur Mathematik, 1982
Norman R Reilly, Petrich Mario, Reilly Norman R   +2 more
exaly  

Completely Regular Semigroups for Which Every Congruence on Each ?-Class Extends to a Congruence on the Whole Semigroup

Communications in Algebra, 2015
exaly