An Erd\H{o}s--Szekeres type result for words with repeats
Combinatorics
2026-05-27 v4
Abstract
We prove an Erd\H{o}s--Szekeres type result for finite words over with repeated values. Specifically, we define a \emph{repeat} in a word to be an occurrence of a value which is not its first occurrence. We define an occurrence of a \emph{pattern} in a word to be a (not necessarily consecutive) subword of that is order isomorphic to . In this note, we show that every word with repeats contains one of the following patterns: , , , , , , . Moreover, when , we show that this is best possible by constructing a word with repeats that does not contain any of these patterns.
Cite
@article{arxiv.2510.23573,
title = {An Erd\H{o}s--Szekeres type result for words with repeats},
author = {Kyle Celano and Abigail Ollson and Niraj Velankar and Jun Yan},
journal= {arXiv preprint arXiv:2510.23573},
year = {2026}
}
Comments
11 pages, 9 figures