A multi-engine solver for quantified Boolean formulas

In this paper we study the problem of yielding robust performances from current state-of-the-art solvers for quantified Boolean formulas (QBFs). Building on top of existing QBF solvers, we implement a new multi-engine solver which can inductively learn its solver selection strategy. Experimental results confirm that our solver is always more robust than each single engine, that it is stable with respect to various perturbations, and that such results can be partially explained by a handful of features playing a crucial role in our solver.