Palindromization

A generalized palindromization map in free monoids

The palindromization map $\psi$ in a free monoid $A^{\*}$ was introduced in 1997 by the first author in the case of a binary alphabet $A$, and later extended by other authors to arbitrary alphabets. Acting on infinite words, $\psi$ generates the …

On some problems related to palindrome closure

In this paper we solve some open problems related to (pseudo)palindrome closure operators and to the infinite words generated by their iteration, that is, standard episturmian and pseudostandard words. We show that if $\vartheta$ is an …

Combinatorial aspects of Sturmian sequences and their generalizations

Pseudopalindrome closure operators in free monoids

We consider involutory antimorphisms $\vartheta$ of a free monoid $A^{\*}$ and their fixed points, called $\vartheta$-palindromes or pseudopalindromes. A $\vartheta$-palindrome reduces to a usual palindrome when $\vartheta$ is the reversal …