2,372 research outputs found
On the Combinatorics of Palindromes and Antipalindromes
We prove a number of results on the structure and enumeration of palindromes
and antipalindromes. In particular, we study conjugates of palindromes,
palindromic pairs, rich words, and the counterparts of these notions for
antipalindromes.Comment: 13 pages/ submitted to DLT 201
Transfinite Lyndon words
In this paper, we extend the notion of Lyndon word to transfinite words. We
prove two main results. We first show that, given a transfinite word, there
exists a unique factorization in Lyndon words that are densely non-increasing,
a relaxation of the condition used in the case of finite words.
In the annex, we prove that the factorization of a rational word has a
special form and that it can be computed from a rational expression describing
the word
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