Abstract (EN):
In this paper we study the regular semigroups weakly generated by a single element x, that is, with no proper regular subsemigroup containing x. We show there exists a regular semigroup F-1 weakly generated by x such that all other regular semigroups weakly generated by x are homomorphic images of F-1. We define F-1 using a presentation where both sets of generators and relations are infinite. Nevertheless, the word problem for this presentation is decidable. We describe a canonical form for the congruence classes given by this presentation, and explain how to obtain it. We end the paper studying the structure of F-1. In particular, we show that the 'free regular semigroup FI2 weakly generated by two idempotents' is isomorphic to a regular subsemigroup of F-1 weakly generated by {xx', x' x}.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
39