Quantified Constraint Handling Rules

TL;DR

This paper introduces QCHR, a dynamic extension of QCSP, enabling the binder to be built during solving, which improves performance on dynamic problems involving quantified constraints.

Contribution

The paper presents QCHR, a novel formalism allowing dynamic binder construction in constraint handling, enhancing flexibility and performance over traditional QCSP methods.

Findings

QCHR outperforms previous QCSP approaches with dynamic binders.

QCHR achieves state-of-the-art performance on static binder problems.

Dynamic binder construction improves solving efficiency.

Abstract

We shift the QCSP (Quantified Constraint Satisfaction Problems) framework to the QCHR (Quantified Constraint Handling Rules) framework by enabling dynamic binder and access to user-defined constraints. QCSP offers a natural framework to express PSPACE problems as finite two-players games. But to define a QCSP model, the binder must be formerly known and cannot be built dynamically even if the worst case won't occur. To overcome this issue, we define the new QCHR formalism that allows to build the binder dynamically during the solving. Our QCHR models exhibit state-of-the-art performances on static binder and outperforms previous QCSP approaches when the binder is dynamic.