Optimal Head-Driven Parsing Complexity for Linear Context-Free Rewriting Systems

Pierluigi Crescenzi1,  Daniel Gildea2,  Andrea Marino1,  Gianluca Rossi3,  Giorgio Satta4
1U of Florence, 2U of Rochester, 3U Roma 2, 4U of Padua


Abstract

We study the problem of finding the best head-driven parsing strategy for Linear Context-Free Rewriting System productions. A head-driven strategy must begin with a specified righthand-side nonterminal (the head) and add the remaining nonterminals one at a time in any order. We show that it is NP-hard to find the best head-driven strategy in terms of either the time or space complexity of parsing.




Full paper: http://www.aclweb.org/anthology/P/P11/P11-1046.pdf