CHR Grammars

TL;DR

This paper introduces CHR Grammars, a flexible bottom-up parsing formalism based on Constraint Handling Rules, capable of modeling complex linguistic phenomena and supporting advanced language analysis techniques.

Contribution

It extends logic programming grammars with context-sensitive rules and the inclusion of extra-grammatical hypotheses, offering a new standard for bottom-up language processing.

Findings

Robust bottom-up parsing with ambiguity handling

Implementation of assumption grammars and abduction techniques

Potential as a new standard for logic programming language grammars

Abstract

A grammar formalism based upon CHR is proposed analogously to the way Definite Clause Grammars are defined and implemented on top of Prolog. These grammars execute as robust bottom-up parsers with an inherent treatment of ambiguity and a high flexibility to model various linguistic phenomena. The formalism extends previous logic programming based grammars with a form of context-sensitive rules and the possibility to include extra-grammatical hypotheses in both head and body of grammar rules. Among the applications are straightforward implementations of Assumption Grammars and abduction under integrity constraints for language analysis. CHR grammars appear as a powerful tool for specification and implementation of language processors and may be proposed as a new standard for bottom-up grammars in logic programming. To appear in Theory and Practice of Logic Programming (TPLP), 2005