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A periodicity property of iterated morphisms

Published online by Cambridge University Press:  18 July 2007

Juha Honkala*
Affiliation:
Department of Mathematics, University of Turku, 20014 Turku, Finland; [email protected]
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Abstract

Suppose ƒ : X* → X* is a morphism and u,v ∈ X*. For every nonnegative integer n, let zn be the longest common prefix of ƒn(u) and ƒn(v), and let un,vn ∈ X* be words such that ƒn(u) = znun and ƒn(v) = znvn. We prove that there is a positive integer q such that for any positive integer p, the prefixes of un (resp. vn) of length p form an ultimately periodic sequence having period q. Further, there is a value of q which works for all words u,v ∈ X*.

Type
Research Article
Copyright
© EDP Sciences, 2007

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References

Ehrenfeucht, A. and Rozenberg, G., Elementary homomorphisms and a solution of the D0L sequence equivalence problem. Theoret. Comput. Sci. 7 (1978) 169183. CrossRef
Ehrenfeucht, A., Lee, K.P. and Rozenberg, G., Subword complexities of various classes of deterministic developmental languages without interactions. Theoret. Comput. Sci. 1 (1975) 5975. CrossRef
G.T. Herman and G. Rozenberg, Developmental Systems and Languages. North-Holland, Amsterdam (1975).
Honkala, J., The equivalence problem for DF0L languages and power series. J. Comput. Syst. Sci. 65 (2002) 377392. CrossRef
G. Rozenberg and A. Salomaa, The Mathematical Theory of L Systems. Academic Press, New York (1980).
G. Rozenberg and A. Salomaa (Eds.), Handbook of Formal Languages. Vol. 1–3, Springer, Berlin (1997).
A. Salomaa, Jewels of Formal Language Theory. Computer Science Press, Rockville, Md. (1981).