no code implementations • 2 Oct 2019 • Johannes Klaus Fichte, Markus Hecher, Andreas Pfandler
More formally, we establish lower bounds for QSAT and treewidth, namely, that under ETH there cannot be an algorithm that solves QSAT of quantifier depth i in runtime significantly better than i-fold exponential in the treewidth and polynomial in the input size.
no code implementations • 16 Jan 2014 • Albert Atserias, Johannes Klaus Fichte, Marc Thurley
We offer a new understanding of some aspects of practical SAT-solvers that are based on DPLL with unit-clause propagation, clause-learning, and restarts.
no code implementations • 8 Jan 2013 • Johannes Klaus Fichte, Stefan Szeider
One cannot transform these two reasoning problems into SAT in polynomial time, unless the Polynomial Hierarchy collapses.
no code implementations • 14 Apr 2011 • Johannes Klaus Fichte, Stefan Szeider
We demonstrate how backdoors can serve as a unifying framework that accommodates several tractable restrictions of ASP known from the literature.