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Pointlike sets for varieties determined by groups
- 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.
- Subjects :
- FOS: Computer and information sciences
Pure mathematics
Membership problem
Formal Languages and Automata Theory (cs.FL)
Semigroup
General Mathematics
010102 general mathematics
20M07, 20M35
Computer Science - Formal Languages and Automata Theory
Group Theory (math.GR)
Characterization (mathematics)
01 natural sciences
Decidability
Aperiodic graph
0103 physical sciences
FOS: Mathematics
010307 mathematical physics
0101 mathematics
Variety (universal algebra)
Mathematics - Group Theory
Mathematics
Separation problem
Subjects
Details
- ISSN :
- 00018708
- Volume :
- 348
- Database :
- OpenAIRE
- Journal :
- Advances in Mathematics
- Accession number :
- edsair.doi.dedup.....7a425d7e98124ff22923ffbd48a9ea6f