The Weighted CFG Constraint

TL;DR

This paper introduces the weighted CFG constraint and presents an efficient propagation algorithm that enforces domain consistency, which can be decomposed into primitive constraints without losing effectiveness.

Contribution

The paper proposes a novel weighted CFG constraint and an associated propagation algorithm with cubic time complexity, enabling efficient constraint solving.

Findings

Propagation algorithm enforces domain consistency in O(n^3|G|) time.

Decomposition into primitive constraints does not hinder propagation.

The approach enhances constraint programming with weighted context-free grammars.

Abstract

We introduce the weighted CFG constraint and propose a propagation algorithm that enforces domain consistency in $O(n^3|G|)$ time. We show that this algorithm can be decomposed into a set of primitive arithmetic constraints without hindering propagation.