%0 Conference Proceedings %T Subshifts, MSO Logic, and Collapsing Hierarchies %+ University of Turku %A Törmä, Ilkka %Z Part 1: Track A: Algorithms, Complexity and Models of Computation %< avec comité de lecture %( Lecture Notes in Computer Science %B 8th IFIP International Conference on Theoretical Computer Science (TCS) %C Rome, Italy %Y Josep Diaz %Y Ivan Lanese %Y Davide Sangiorgi %I Springer %3 Theoretical Computer Science %V LNCS-8705 %P 111-122 %8 2014-09-01 %D 2014 %R 10.1007/978-3-662-44602-7_10 %K subshift %K MSO logic %K quantifier alternation %Z Computer Science [cs]Conference papers %X We use monadic second-order logic to define two-dimensional subshifts, or sets of colorings of the infinite plane. We present a natural family of quantifier alternation hierarchies, and show that they all collapse to the third level. In particular, this solves an open problem of [Jeandel & Theyssier 2013]. The results are in stark contrast with picture languages, where such hierarchies are usually infinite. %G English %Z TC 1 %Z TC 2 %Z WG 2.2 %2 https://inria.hal.science/hal-01402035/document %2 https://inria.hal.science/hal-01402035/file/978-3-662-44602-7_10_Chapter.pdf %L hal-01402035 %U https://inria.hal.science/hal-01402035 %~ IFIP-LNCS %~ IFIP %~ IFIP-TC %~ IFIP-TC2 %~ IFIP-LNCS-8705 %~ IFIP-TCS %~ IFIP-WG2-2