16 citations · 31 across the 15 of their papers we have counts for
20 papers
Decision Problems on Copying and Shuffling
Vesa Halava, Tero Harju, Dirk Nowotka +1
We study decision problems of the form: given a regular or linear context-free language , is there a word of a given fixed form in , where given fixed forms are based on word…
On the Self Shuffle Language
Pamela Fleischmann, Tero Harju, Lukas Haschke +2
The shuffle product \(u\shuffle v\) of two words \(u\) and \(v\) is the set of all words which can be obtained by interleaving \(u\) and \(v\). Motivated by the paper \emph{The Shu…
A recursive function coding number theoretic functions
Vesa Halava, Tero Harju, Teemu Pirttimäki
We show that there exists a fixed recursive function such that for all functions , there exists an injective function $c_h\colon \mathbb{N}\to…
On Bi-infinite and Conjugate Post Correspondence Problems
Olivier Finkel, Vesa Halava, Tero Harju +1
We study two modifications of the Post Correspondence Problem (PCP), namely 1) the bi-infinite version, where it is asked whether there exists a bi-infinite word such that two give…
A Note on Squares in Binary Words
Tero Harju
We consider words over a binary alphabet. A word is overlap-free if it does not have factors (blocks of consecutive letters) of the form for nonempty . Let de…
Critical factorisation in square-free words
Tero Harju
A position in a word is critical if the minimal local period at is equal to the global period of . According to the Critical Factorisation Theorem all words of lengt…