Semidirectly closed pseudovarieties of locally trivial semigroups.
Solvability of equations in varieties of universal algebras.
Some pseudovariety joins involving the pseudovariety of finite groups.
Some quasi-ordered classes of finite commutative semigroups.
Some regular quasivarieties of commutative binary modes
Irregular (quasi)varieties of groupoids are (quasi)varieties that do not contain semilattices. The regularization of a (strongly) irregular variety of groupoids is the smallest variety containing and the variety of semilattices. Its quasiregularization is the smallest quasivariety containing and . In an earlier paper the authors described the lattice of quasivarieties of cancellative commutative binary modes, i.e. idempotent commutative and entropic (or medial) groupoids. They are all irregular...
Some results on the dot-depth hierarchy.
Subsemigroups of completely simple semigroups. III.
Sur le rang et la définissabilité des opérations implicites dans les classes d'algèbres