A regularity lemma and twins in words

Maria Axenovich, Yury Person, Svetlana Puzynina

For a word $S$, let $f(S)$ be the largest integer $m$ such that there are two disjoints identical (scattered) subwords of length $m$. Let $f(n, Σ) = \min \{f(S): S \text{is of leng…