Supported by the National Natural Science Foundation of China (Grant No.10571077);the Natural Science Foundation of Gansu Province (Grant No.3ZS032-A25-017)
In this paper, all subvarieties of the varieties Ak (k ∈N) generated by aperiodic commutative semigroups are characterized. Based on this characterization, the structure of lattice of subvarieties of Ak is investig...
supported by National Natural Science Foundation of China (Grant No.10571077);Natural Science Foundation of Gansu Province (Grant No.3ZS052-A25-017)
Characterization theorems for abundant sernigroups having a quasi-ideal quasi-adequate transversal are obtained. Our results generalize and amplify the related results of Satio on regular semigroup obtained in 1985 an...
the EYTP of MOE of China,the National Natural Science Foundation of China(No.10571077);the Natural Science Foundation of Gansu Province(3ZS052-A25-017)
The join A ∨ B of two semigroup varieties A and B is investigated. The latrine of subvarieties of A ∨ B is completely described, It is shown that this lattice is finite and non-modular and that all varieties in it a...