On trivializers and subsemigroups.
. Semigroups and formal languages. Proceedings of the international conference in honour of the 65th birthday of Donald B. McAlister. Lisboa, Portugal, July 12–15, 2005.: Hackensack, NJ: World Scientific, 2007. Abstract
The aim of this paper is to develop the calculus of trivializers for subsemigroups. Given a finite presentation defining a semigroup S and a trivializer of the Squier complex of , we obtain an infinite trivializer of the Squier complex of a finite presentation defining a subsemigroup of S. Also, we give a method to find finite trivializers for special subsemigroups and hence to show that those subsemigroups have finite derivation type (FDT). An application of this method is given: we prove that if is a band of monoids having FDT, then so does Sα, for any α ∈Y.