On the star-height of subword counting languages and their relationship to Rees zero-matrix semigroups
Given a word w over a finite alphabet, we consider, in three special cases, the generalised star-height of the languages in which w occurs as a contiguous subword (factor) an exact number of times and of the languages in which w occurs as a contiguous subword modulo a fixed number, and prove that in...
Saved in:
Published in | Theoretical computer science Vol. 653; pp. 87 - 96 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
15.11.2016
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Given a word w over a finite alphabet, we consider, in three special cases, the generalised star-height of the languages in which w occurs as a contiguous subword (factor) an exact number of times and of the languages in which w occurs as a contiguous subword modulo a fixed number, and prove that in each case it is at most one. We use these combinatorial results to show that any language recognised by a Rees (zero-)matrix semigroup over an Abelian group is of generalised star-height at most one. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0304-3975 1879-2294 |
DOI: | 10.1016/j.tcs.2016.09.024 |