Avoiding Patterns in the Abelian Sense
James D. Currie, Václav Linek · Canadian Journal of Mathematics · 2001
Abstract We classify all 3 letter patterns that are avoidable in the abelian sense. A short list of four letter patterns for which abelian avoidance is undecided is given. Using a generalization of Zimin words we deduce some properties of ω-words avoiding these patterns.