The language intersection problem for non-recursive context-free grammars☆

https://doi.org/10.1016/j.ic.2004.03.004Get rights and content
Under an Elsevier user license
open archive

Abstract

We prove that, given as input two context-free grammars, deciding non-emptiness of intersection of the two generated languages is PSPACE-complete if at least one grammar is non-recursive. The problem remains PSPACE-complete when both grammars are non-recursive and deterministic. Also investigated are generalizations of the problem to several context-free grammars, of which a certain number are non-recursive.

Keywords

Formal languages
Context-free grammars
Computational complexity
Parsing algorithms

Cited by (0)

☆

We thank Harry B. Hunt III for helpful correspondence. We are indebted to an anonymous referee for proposals leading to most of the content of Section 3.

1

Supported by the PIONIER Project Algorithms for Linguistic Processing, funded by NWO (Dutch Organization for Scientific Research).

2

Partially supported by MIUR under project PRIN No. 2003091149_005.

Copyright © 2004 Elsevier Inc. All rights reserved.