Some Remarks on Almost Periodic Sequences and Languages
Abstract
Almost periodicity has been considered in Formal Language Theory in connection with some topics in Symbolic Dynamics. In (Păun and Marcus, Bulletin of EATCS 53 (1994)) some problems concerning this property are raised. For instance it is asked whether there exists some almost periodic word $\alpha$ such that $Sub(\alpha)$, the set of its finite factors, is context-free non-regular. We answer negatively (even in a stronger form) this question, as well as discussing other related topics.
- Publication:
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arXiv e-prints
- Pub Date:
- November 2022
- DOI:
- 10.48550/arXiv.2211.14613
- arXiv:
- arXiv:2211.14613
- Bibcode:
- 2022arXiv221114613I
- Keywords:
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- Computer Science - Formal Languages and Automata Theory
- E-Print:
- Reconstructed source file of a paper originally published in 1995 in a volume currently without an online version (and with limited availability). Uploaded in order to ensure the online availability (and preservation) of the paper. This version faithfully reproduces the original, except for the addition of a note about the solution of Open Problem 3 and the correction of some minor typos