Finite orthodox locally idempotent semigroups having no finite basis of biidentities

Free profinite locally idempotent and locally commutative semigroups

This paper is concerned with the structure of semigroups of implicit operations on the pseudovariety LSl of finite locally idempotent and locally commutative semigroups. We depart from a general result of Almeida and Weil to give two descriptions of these semigroups: the first in terms of infinite words, and the second in terms of infinite and bi-infinite words. We then derive some applications...

Finite Idempotent Inverse Monoid Presentations

Several decidability problems for finite idempotent presentations of inverse monoids are solved, giving also insight into their structure. Besides providing a new elementary solution for the problem, solutions are obtained for the following problems: computing the maximal subgroups, being combinatorial, being semisimple, being fundamental, having infinite D-classes. The word problem for the lea...

Dynamics of Finite Semigroups

Dualisability of Finite Semigroups

We describe the inherently non-dualisable finite algebras from some semigroup related classes. The classes for which this problem is solved include the variety of bands, the pseudovariety of aperiodic monoids, commutative monoids, and (assuming a reasonable conjecture in the literature) the varieties of all finite monoids and finite inverse semigroups. The first example of an inherently non-dua...

Locally finite basic classical simple Lie superalgebras

In this work, we study direct limits of finite dimensional basic classical simple Lie superalgebras and obtain the conjugacy classes of Cartan subalgebras under the group of automorphisms.