Blanchet-Sadri et al. have shown that Avoidability, or the problem of deciding the avoidability of a finite set of partial words over an alphabet of size k 2, is NP-hard [Theoret...
We study the Monadic Second Order (MSO) Hierarchy over infinite pictures, that is tilings. We give a characterization of existential MSO in terms of tilings and projections of tili...
We show here how to construct a cellular automaton whose asymptotic set (the set of configurations it converges to) is maximally complex: it contains only configurations of maximal...
Abstract. We study expansions in non-integer negative base - introduced by Ito and Sadahiro [7]. Using countable automata associated with (-)-expansions, we characterize the case w...
Seki et al. (1991) proved a rather weak pumping lemma for multiple context-free languages, which says that any infinite m-multiple context-free language contains a string that is p...