Local finiteness for Green relations in varieties of semigroups
26/04/2018 26/04/2018, 14h30
Filipa Soares de Almeida, ISEL-IPL / CEMAT-Ciências
Centre of Mthemathics of the University of Porto
In this talk, we explore a notion that sits between the concept of locally finite variety and that of periodic variety, using the inescapable Green's relations. Namely, a variety is said to be K-finite, where K stands for any of the Green's relations, if every finitely generated semigroup in this variety has but finitely many K-classes. Our characterization uses the language of "forbidden objects".