Shakashaka is a pencil-and-paper puzzle proposed by Guten and popularized by the Japanese publisher Nikoli (like Sudoku). We determine the computational complexity by proving that Shakashaka is NP-complete, and furthermore that counting the number of solutions if #P-complete. Next we formulate Shakashaka as an integer programming (IP) problem, and show that an IP solver can solve every instance...

Precise complexity results are derived for the model checking problems for MTL (metric temporal logic) and TPTL (timed propositional temporal logic) on (in)finite data words and deterministic one-counter machines. Depending on the number of register variables and the encoding of numbers in constraints (unary or binary), the complexity is either P-complete or PSPACE-complete.

Unfoldings are a technique for verification of concurrent and distributed systems introduced by McMillan. The method constructs a finite complete prefix, which can be seen as a symbolic representation of an interleaved reachability graph. We show that model checking a fixed size formula of several temporal logics, including LTL, CTL, and CTL∗, is PSPACE-complete in the size of a finite complete...

We develop a geometric approach to definable sets in differentially closed fields, with emphasis on the question of orthogonality to a given strongly minimal set. Equivalently, within a family of ordinary differential equations, we consider those equations that can be transformed, by differential-algebraic transformations, so as to yield solutions of a given fixed first-order ODE X. We show tha...

We completely classify the computational complexity of the basic achievement and maintenance agent design problems in bounded environments when these problems are parameterized by the number of environment states and the number of agent actions. The different problems are P-complete, NP-complete, co-NP-complete or PSPACE-complete (when they are not trivial). We also consider alternative achieve...