“…[8,9,10]) or for nite semigroups and monoids (e.g. [2,6,20,21,22,23,24,29,31,33]). Just to mention some of the most recent results: following up on [2], Klíma nished the characterization for the transformation monoids [24], or Gorazd and Krzaczkowski characterized the complexity of these problems for all two-element general algebras [9,10].…”