Abstract
We contribute to the study of square-free words. The classical notion of a square-free word has a natural generalization to partial words, studied in several papers since 2008. We prove that the maximal density of wildcards in the ternary infinite square-free partial word is surprisingly big: 3/16. In addition, we introduce a related characteristic of infinite square-free words, called flexibility, and find its values for some interesting words and classes of words.
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Notes
- 1.
As mentioned above, some sets do not have density; to avoid additional notions we postulate that upper (lower) bounds on flexibility should work for upper (resp., lower) densities of the corresponding wildcard sets.
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Gasnikov, D., Shur, A.M. (2016). Ternary Square-Free Partial Words with Many Wildcards. In: Brlek, S., Reutenauer, C. (eds) Developments in Language Theory. DLT 2016. Lecture Notes in Computer Science(), vol 9840. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-53132-7_15
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DOI: https://doi.org/10.1007/978-3-662-53132-7_15
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