3 papers
math.GR2020
The Karoubi envelope of the mirage of a subshift
Alfredo Costa, Benjamin Steinberg
We study a correspondence associating to each subshift of a subcategory of the Karoubi envelope of the free profinite semigroup generated by . The o…
math.GR2019
Bases for pseudovarieties closed under bideterministic product
Alfredo Costa, Ana Escada
We show that if is a semigroup pseudovariety containing the finite semilattices and contained in , then it has a basis of pseudoidentities between finite…
math.DS2018
Symbolic dynamics and semigroup theory
Alfredo Costa
A major motivation for the development of semigroup theory was, and still is, its applications to the study of formal languages. Therefore, it is not surprising that the correspond…