Continued the development of the theory of finite semigroups through a
profinite approach, together with its applications in computer
science. The following deserve special mention: structural properties
of the profinite semigroups of equational classes of (multivariate)
functions on a finite set, particularly in the Boolean case (joint
work with M. Couceiro and T. Waldhauser); separation of regular
languages by languages of a fixed type, alias the two
element-pointlike set problem for finite semigroups, and related
problems (joint with J. C. Costa and M. Zeitoun); several independent
construction procedures for pseudovarieties of ordered semigroups
closed under taking semigroups of downsets (with A. Cano, O. Klíma,
and J.-E. Pin).