Algebra Seminar talk

2011-09-16
Libor Polak
Identity problems, solvability of equations and unification in varieties of semigroups related to varieties of groups

Abstract:
In this survey we consider three kinds of algorithmic questions concerning varieties of semigroups. We are interested in identity problems, in the solvability of a system of equations and in the structure of all solutions of a given system.
We study them in significant varieties of semigroups, monoids, groups, completely simple semigroups, completely regular semigroups (in particular semigroups satisfying the identity x^r =x) and involutary semigroups (in particular star regular semigroups and inverse semigroups).