Combinatorial semigroup theory: generating sets for semigroups and defining semigroups by presentations (generators and defining relations); presentations for substructures and algebraic constructions;
Subsemigroups: index and rank;
Group and semigroup presentations;
Transformation semigroups: properties of finite and infinite semigroups of mappings from a set into itself;
Machine and languages (theoretical computer science) in algebra: automatic structures, decidability;
Combinatorics of permutations, words, etc: pattern classes, decidability questions in combinatorics;
Computational algebra: algorithms and packages for computing with algebraic structures.