Pointlike sets for varieties determined by groups
Group Theory
2018-01-16 v1 Formal Languages and Automata Theory
Abstract
For a variety of finite groups , let denote the variety of finite semigroups all of whose subgroups lie in . We give a characterization of the subsets of a finite semigroup that are pointlike with respect to . Our characterization is effective whenever has a decidable membership problem. In particular, the separation problem for -languages is decidable for any decidable variety of finite groups . This generalizes Henckell's theorem on decidability of aperiodic pointlikes.
Cite
@article{arxiv.1801.04638,
title = {Pointlike sets for varieties determined by groups},
author = {Samuel J. v. Gool and B. Steinberg},
journal= {arXiv preprint arXiv:1801.04638},
year = {2018}
}