Theory of Computing Systems

We study the power of entropy compression in proving avoidance results in combinatorics on words. Namely, we analyze variants of a simple algorithm that transforms an input word into a word avoiding repetitions of prescribed type. This ...$\mathrm{}\frac{\mathrm{}}{}$$\mathrm{}$$\mathrm{}$${\mathrm{}\frac{\mathrm{}}{}}^{}$

This paper studies obstructions to preservation of return sets by episturmian morphisms. We show, by way of an explicit construction, that infinitely many obstructions exist. This generalizes and improves an earlier result about Sturmian ...

We define a new class of ternary sequences that are 2-balanced. These sequences are obtained by colouring of Sturmian sequences. We show that the class contains sequences of any given letter frequencies. We provide an upper bound on factor and ...

It is known that the set of solutions of any constant-free three-variable word equation can be represented using parametric words, and the number of numerical parameters and the level of nesting in these parametric words is at most logarithmic ...

Jumping automata are finite automata that read their input in a non-consecutive manner, disregarding the order of the letters in the word. We introduce and study jumping automata over infinite words. Unlike the setting of finite words, which has ...

Firstly studied by Kempa and Prezza in 2018 as the unifying idea behind text compression algorithms, string attractors have become a compelling object of theoretical research within the community of combinatorics on words. In this context, they ...

Parikh-collinear morphisms have the property that all the Parikh vectors of the images of letters are collinear, i.e., the associated adjacency matrix has rank 1. In the conference DLT–WORDS 2023 we showed that fixed points of Parikh-collinear ...

$\mathsf{FC}$ is a finite model variant on the theory of concatenation, $\mathsf{FC}[\mathsf{REG}]$ extends $\mathsf{FC}$ with regular constraints. This paper considers the languages generated by their conjunctive query fragments, FC-CQ and FC[REG]-CQ. We compare the expressive power of $\mathsf{...}\mathsf{}\mathsf{}$$\mathsf{}\mathsf{}$$\mathsf{}\mathsf{}\mathsf{}$$\mathsf{}\mathsf{}$$\mathsf{}$

A real number is called left-computable if there exists a computable increasing sequence of rational numbers converging to it. In this article we are investigating a proper subset of the left-computable numbers. We say that a real number x is ...$\mathbb{}\mathbb{}$${}_{\mathrm{}}^{}{\mathrm{}}^{}$$\mathbb{}\mathbb{}$${}_{\mathrm{}}^{}{\mathrm{}}^{}$