On the fixed points of the iterated pseudopalindromic closure operator
First introduced in the study of the Sturmian words by de Luca in 1997, iterated palindromic closure was generalized to pseudopalindromes by de Luca and De Luca in 2006. This operator allows one to construct words with infinitely many pseudopalindromic prefixes, called pseudostandard words. We provide here several combinatorial properties of the fixed points under iterated pseudopalindromic closure. (C) 2010 Elsevier BM. All rights reserved.
fixed point pseudopalindrome palindromic closure sturmian word pseudostandard word involutory antimorphism