2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/224891We show that the set of binary words containing overlaps is not unambiguously context-free and that the set of ternary words containing overlaps is not context-free. We also show that the set of binary words that are not subwords of the Thue-Morse word is not unambiguously context-free.8 pagesCombinatoricsFormal Languages and Automata Theory68R15text