Authors: Noriko Tomuro
Journal-ref: Proceedings of the 34th Annual Meeting of the Association for Computational Linguistics, Santa Cruz, CA. pp. 381-383.

Abstract

A left-corner parsing algorithm with top-down filtering has been reported to show very efficient performance for unification-based systems. However, due to the nontermination of parsing with left-recursive grammars, top-down constraints must be weakened. In this paper, a general method of maximizing top-down constraints is proposed. The method provides a procedure to dynamically compute $*restrictor*$, a minimum set of features involved in an infinite loop for every propagation path; thus top-down constraints are maximally propagated.