Standard automata and semidirect products of transformation semigroups

compactifications and representations of transformation semigroups

this thesis deals essentially (but not from all aspects) with the extension of the notion of semigroup compactification and the construction of a general theory of semitopological nonaffine (affine) transformation semigroup compactifications. it determines those compactification which are universal with respect to some algebric or topological properties. as an application of the theory, it is i...

Semidirect Products of Ordered Semigroups

Semidirect Products of Ordered Semigroups

Semidirect products of ordered semigroups

We introduce semidirect and wreath products of finite ordered semigroups and extend some standard decomposition results to this case.

Semidirect Products of Regular Semigroups

Within the usual semidirect product S ∗ T of regular semigroups S and T lies the set Reg (S ∗ T ) of its regular elements. Whenever S or T is completely simple, Reg (S ∗T ) is a (regular) subsemigroup. It is this ‘product’ that is the theme of the paper. It is best studied within the framework of existence (or e-) varieties of regular semigroups. Given two such classes, U and V, the e-variety U...