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.