Each regular code is included in a maximal regular code
Elementary ...-languages and finite semilattices of groups.
Equational description of pseudovarieties of homomorphisms
The notion of pseudovarieties of homomorphisms onto finite monoids was recently introduced by Straubing as an algebraic characterization for certain classes of regular languages. In this paper we provide a mechanism of equational description of these pseudovarieties based on an appropriate generalization of the notion of implicit operations. We show that the resulting metric monoids of implicit operations coincide with the standard ones, the only difference being the actual interpretation of pseudoidentities....
Equational description of pseudovarieties of homomorphisms
The notion of pseudovarieties of homomorphisms onto finite monoids was recently introduced by Straubing as an algebraic characterization for certain classes of regular languages. In this paper we provide a mechanism of equational description of these pseudovarieties based on an appropriate generalization of the notion of implicit operations. We show that the resulting metric monoids of implicit operations coincide with the standard ones, the only difference being the actual interpretation of pseudoidentities. As...
Equations and dot-depth one.
Equidivisible Kleene monoids and the Elgot-Mezei theorem.
Expletives in languages and middle units in semigroups.