D0L sequences
نویسندگان
چکیده
منابع مشابه
On sequences defined by D0L power series
We study D0L power series over commutative semirings. We show that a sequence (cn)n 0 of nonzero elements of a eld A is the coe cient sequence of a D0L power series if and only if there exist a positive integer k and integers i for 1 i k such that cn+k = c 1 n+k 1c 2 n+k 2 : : : c k n for all n 0. As a consequence we solve the equivalence problem of D0L power series over computable elds. TUCS R...
متن کاملOn D0L power series
We study D0L power series. We show how elementary morphisms introduced by Ehrenfeucht and Rozenberg can be used in connection with power series, characterize the sequences of rational numbers and integers which can be appear as coe cients in D0L power series and establish various decidability results. TUCS Research Group Mathematical Structures of Computer Science
متن کاملWatson-Crick D0L Systems
D0L systems constitute the simplest and most widely studied type of Lindenmayer systems. They have the remarkable property of generating their language as a (word) sequence and, consequently, are very suitable for modeling growth properties. In this paper a new type of D0L systems is introduced, where the parallelism presented in L systems is combined with the paradigm of (Watson-Crick) complem...
متن کاملOn the D0L Repetition Threshold
The repetition threshold is a measure of the extent to which there need to be consecutive (partial) repetitions of finite words within infinite words over alphabets of various sizes. Dejean’s Conjecture, which has been recently proven, provides this threshold for all alphabet sizes. Motivated by a question of Krieger, we deal here with the analogous threshold when the infinite word is restricte...
متن کاملOn fairness of D0L systems
Aword is called fair if it contains, for each pair of distinct symbols a, b, the same number of occurrences of the scattered subword ab as of ba. We prove that if the first k + 1 words in the sequence generated by a D0L system over a k-letter alphabet are fair then all words in the sequence are fair. © 2007 Elsevier B.V. All rights reserved.
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ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 1974
ISSN: 0012-365X
DOI: 10.1016/s0012-365x(74)80009-9