Return words in Sturmian and episturmian words
Jacques Justin, Laurent Vuillon (2010)
RAIRO - Theoretical Informatics and Applications
Similarity:
Considering each occurrence of a word in a recurrent infinite word, we define the set of return words of to be the set of all distinct words beginning with an occurrence of and ending exactly just before the next occurrence of in the infinite word. We give a simpler proof of the recent result (of the second author) that an infinite word is Sturmian if and only if each of its factors has exactly two return words in it. Then, considering episturmian infinite words, which are a natural generalization...