Deciding the inequivalence of context-free grammars with 1-letter terminal alphapet is \(\sum ^ p_ 2\)-complete
type: Item
instance of: scholarly article
title: Deciding the inequivalence of context-free grammars with 1-letter terminal alphapet is \(\sum ^ p_ 2\)-complete
zbMATH Open document ID: 0556.68040
DOI: 10.1016/0304-3975(84)90092-6
author: Dung T. Huynh
published in: Theoretical Computer Science
publication date: 1984-01-01T00:00:00Z
review text: This paper deals with the computational complexity of two fundamental decision problems for context-free grammars with 1-letter terminal alphabet, namely the membership and inequivalence problems. The main results of this paper are: (1) The membership problem is log-complete for NP, and (2) The inequivalence problem is log-complete for \(\sum^ p_ 2\). In particular, the second result implies that the inequivalence problem for this restricted grammar class is in PSPACE, thereby setting an open question posed by \textit{H. B. Hunt III}, \textit{D. J. Rosenkrantz} and \textit{T. G. Szymanski} [J. Comput. Syst. Sci. 12, 222-268 (1976; Zbl 0334.68044)].
Mathematics Subject Classification ID: 68Q45
Mathematics Subject Classification ID: 68Q25
zbMATH DE Number: 3887098
zbMATH Keywords: equivalence
zbMATH Keywords: computational complexity
zbMATH Keywords: decision problems
zbMATH Keywords: context-free grammars
zbMATH Keywords: membership
MaRDI profile type: Publication
full work available at URL: 0304-3975(84)90092-6
OpenAlex ID: W2007431032
cites work: Q3888558
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description: scientific article; zbMATH DE number 3887098