Semi-automorphisms of transformation semigroups
Semigroups and their lattice of congruences.
Semigroups and their lattice of congruences II.
Semigroups and their natural order
Semigroups for which all homomorphic images have complemented lattices of congruences.
Semigroups for which the continuum congruences form finite chains.
Semigroups which admit few embeddings
Semigroups with Boolean Congruence Lattices.
Semilattice decomposition of semigroups.
Semilattices are globally determined.
Solvability in inverse semigroups.
Some aspects of Green's relations on periodic semigroups
Some results on congruences on R-unipotent semigroups.
Some results on C-varieties
In an earlier paper, the second author generalized Eilenberg's variety theory by establishing a basic correspondence between certain classes of monoid morphisms and families of regular languages. We extend this theory in several directions. First, we prove a version of Reiterman's theorem concerning the definition of varieties by identities, and illustrate this result by describing the identities associated with languages of the form (a1a2...ak)+, where a1,...,ak are distinct letters. Next,...
Some results on -varieties
In an earlier paper, the second author generalized Eilenberg’s variety theory by establishing a basic correspondence between certain classes of monoid morphisms and families of regular languages. We extend this theory in several directions. First, we prove a version of Reiterman’s theorem concerning the definition of varieties by identities, and illustrate this result by describing the identities associated with languages of the form , where are distinct letters. Next, we generalize the notions...
S-sets and semigroups of quotients.
Subsemigroups of completely simple semigroups II.
Sur les bandes réticulées.
Sur les transductions reconnaissables
Symons’ -congruence on sandwich semigroups