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Return words in Sturmian and episturmian words

Published online by Cambridge University Press:  15 April 2002

Jacques Justin
Affiliation:
LIAFA, Université Paris VII, Case 7014, 2 place Jussieu, 75251 Paris Cedex 05, France; (Jacques.Justin@liafa.jussieu.fr)
Laurent Vuillon
Affiliation:
LIAFA, Université Paris VII, Case 7014, 2 place Jussieu, 75251 Paris Cedex 05, France; (Laurent.Vuillon@liafa.jussieu.fr)
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Abstract

Considering each occurrence of a word w in a recurrent infinite word, we define the set of return words of w to be the set of all distinct words beginning with an occurrence of w and ending exactly just before the next occurrence of w 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 of Sturmian words, we study the position of the occurrences of any factor in such infinite words and we determinate the return words. At last, we apply these results in order to get a kind of balance property of episturmian words and to calculate the recurrence function of these words.

Keywords

Type
Research Article
Copyright
© EDP Sciences, 2000

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References

J.-P. Allouche, J.L. Davison, M. Queffélec and L.Q. Zamboni, Transcendence of Sturmian or morphic continued fractions. Preprint (1999).
Arnoux, P. and Rauzy, G., Représentation géométrique de suites de complexité 2n+1. Bull. Soc. Math. France 119 (1991) 199-215. CrossRef
J. Berstel and P. Séébold, Sturmian words, edited by M. Lothaire, Algebraic combinatorics on Words (to appear).
J. Cassaigne, Ideas for a proof of Rauzy's conjecture on the recurrence functions of infinite words, talk in Rouen ``words 1999''.
N. Chekhova, P. Hubert and A. Messaoudi, Propriétés combinatoires,ergodiques et arithmétiques de la substitution de Tribonacci. Prepublication 98-24 IML.
de Luca, A., Sturmian words: Structure, Combinatorics and their Arithmetics. Theoret. Comput. Sci. 183 (1997) 45-82. CrossRef
X. Droubay, J. Justin and G. Pirillo, Episturmian words and some constructions of Rauzy and de Luca. Theoret. Comput. Sci. (to appear).
Durand, F., A characterization of substitutive sequences using return words. Discrete Math. 179 (1998) 89-101. CrossRef
F. Durand, Contributions à l'étude des suites et systèmes dynamiques substitutifs. Ph.D. Thesis, Université de la Méditerranée, Aix-Marseille II (1996).
I. Fagnot and L. Vuillon, Generalized balances in Sturmian words. Prepublication LIAFA 2000/02.
Hedlund, G.A. and Morse, M., Symbolic dynamics II: Sturmian trajectories. Amer. J. Math. 62 (1940) 1-42. CrossRef
Holton, C. and Zamboni, L.Q., Geometric realizations of substitutions. Bull. Soc. Math. France 126 (1998) 149-179. CrossRef
J. Justin and G. Pirillo, Episturmian words and episturmian morphisms. Prepublication LIAFA 2000/23.
Vuillon, L., A characterization of Sturmian words by return words. European J. Combin. 22 (2001) 263-275. CrossRef