A generator of morphisms for infinite words
LaBRI, Université Bordeaux I, 351, cours de la Libération, 33405 Talence Cedex, France; firstname.lastname@example.org
We present an algorithm which produces, in some cases, infinite words avoiding both large fractional repetitions and a given set of finite words. We use this method to show that all the ternary patterns whose avoidability index was left open in Cassaigne's thesis are 2-avoidable. We also prove that there exist exponentially many -free ternary words and -free 4-ary words. Finally we give small morphisms for binary words containing only the squares 2, 12 and (01)² and for binary words avoiding large squares and fractional repetitions.
Mathematics Subject Classification: 68R15
© EDP Sciences, 2006