Using Unit Propagation with Universal Reduction in DQBF Preprocessing

Abstract: Several effective preprocessing techniques for Boolean formulas with and without quantifiers use unit propagation to simplify the formula. Among these techniques are vivification, unit propagation look-ahead (UPLA), and the identification of redundant clauses as so-called quantified resolution asymmetric tautologies (QRAT). For quantified Boolean formulas (QBFs), these techniques have been extended to allow the application of universal reduction during unit propagation, which makes the techniques more effective. In this paper, we prove that the generalization of QBF to dependency quantified Boolean formulas (DQBFs) also allows the application of universal reduction during these preprocessing techniques.