QCSP made practical by virtue of restricted quantification

Abstract

The QCSP + language we introduce extends the framework of Quantified Constraint Satisfaction Problems (QCSPs) by enabling us to neatly express restricted quantifications via a chain of nested CSPs to be interpreted as alternately conjuncted and disjuncted. Restricted quantifiers turn out to be a convenient solution to the crippling modeling issues we encounter in QCSP and—surprisingly— they help to reuse propagation technology and to prune the search space. Our QCSP + solver—which also handles arithmetic and global constraints— exhibits state-of-the-art performances.