On the Cooperation of the Constraint Domains H, R and FD in CFLP

TL;DR

This paper introduces a computational model and implementation for cooperative constraint solving across multiple domains within a CFLP framework, supporting complex declarative programming features.

Contribution

It presents a new cooperative model for constraint domains in CFLP and an implementation on the TOY system, demonstrating soundness, completeness, and efficiency.

Findings

The model is sound and complete with respect to the CFLP semantics.

The implementation supports cooperation of H, R, and FD domains.

Benchmarks show the system's efficiency compared to related approaches.

Abstract

This paper presents a computational model for the cooperation of constraint domains and an implementation for a particular case of practical importance. The computational model supports declarative programming with lazy and possibly higher-order functions, predicates, and the cooperation of different constraint domains equipped with their respective solvers, relying on a so-called Constraint Functional Logic Programming (CFLP) scheme. The implementation has been developed on top of the CFLP system TOY, supporting the cooperation of the three domains H, R and FD, which supply equality and disequality constraints over symbolic terms, arithmetic constraints over the real numbers, and finite domain constraints over the integers, respectively. The computational model has been proved sound and complete w.r.t. the declarative semantics provided by the $CFLP$ scheme, while the implemented system has been tested with a set of benchmarks and shown to behave quite efficiently in comparison to the closest related approach we are aware of. To appear in Theory and Practice of Logic Programming (TPLP)