Identify a string x over {0,1} with the positive integer
whose binary representation is 1x. We say that a self-reduction is
k-local if on input x all queries belong to {x-1,...,x-k}. We show
that all k-locally self-reducible sets belong to PSPACE. However, the
power of k-local self-reductions changes drastically between ... more >>>

Tree-width is a well-studied parameter of structures that measures their similarity to a tree. Many important NP-complete problems, such as Boolean satisfiability (SAT), are tractable on bounded tree-width instances. In this paper we focus on the canonical PSPACE-complete problem QBF, the fully-quantified version of SAT. It was shown by Pan ... more >>>