| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 436644 | Theoretical Computer Science | 2007 | 7 Pages |
Abstract
By introducing the notion of mirror substitution, we show that, given a substitutive sequence over two letters, it is palindromic (that is, it contains arbitrarily long palindromes) if and only if its language is mirror-invariant (that is, it is closed under the mirror image map). Then we solve a question of Hof, Knill and Simon in the 2-letter case, and also, by constructing a counterexample, we give a negative answer to the open problem 4 in the webpage: http://iml.univ-mrs.fr/~bernat/openquestions.html.
Related Topics
Physical Sciences and Engineering
Computer Science
Computational Theory and Mathematics
