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arXiv · 1401.2294

Quantifier Extensions of Multidimensional Sofic Shifts

Ilkka Törmä
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Abstract

We define a pair of simple combinatorial operations on subshifts, called existential and universal extensions, and study their basic properties. We prove that the existential extension of a sofic shift by another sofic shift is always sofic, and the same holds for the universal extension in one dimension. However, we also show by a construction that universal extensions of two-dimensional sofic shifts may not be sofic, even if the subshift we extend by is very simple.

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Ilkka Törmä. 2014-01-10. Quantifier Extensions of Multidimensional Sofic Shifts. https://arxiv.org/abs/1401.2294

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