%0 Journal Article %T Quantifier Extensions of Multidimensional Sofic Shifts %A Ilkka T£¿rm£¿ %J Computer Science %D 2014 %I arXiv %X 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. %U http://arxiv.org/abs/1401.2294v2