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Pointlike sets for varieties determined by groups

Authors :
Benjamin Steinberg
Samuel J. van Gool
Source :
Advances in Mathematics. 348:18-50
Publication Year :
2019
Publisher :
Elsevier BV, 2019.

Abstract

For a variety of finite groups $\mathbf H$, let $\overline{\mathbf H}$ denote the variety of finite semigroups all of whose subgroups lie in $\mathbf H$. We give a characterization of the subsets of a finite semigroup that are pointlike with respect to $\overline{\mathbf H}$. Our characterization is effective whenever $\mathbf H$ has a decidable membership problem. In particular, the separation problem for $\overline{\mathbf H}$-languages is decidable for any decidable variety of finite groups $\mathbf H$. This generalizes Henckell's theorem on decidability of aperiodic pointlikes.

Details

ISSN :
00018708
Volume :
348
Database :
OpenAIRE
Journal :
Advances in Mathematics
Accession number :
edsair.doi.dedup.....7a425d7e98124ff22923ffbd48a9ea6f