Publication Details
Phrase-Structure Grammars: Normal Forms and Reduction
Meduna Alexander, prof. RNDr., CSc. (DIFS FIT BUT)
Zemek Petr, Ing. (DIFS FIT BUT)
formal languages, phrase-structure grammars, normal forms
This paper establishes two new normal forms for phrase-structure grammars in which both context-free rules and non-context-free rules are in prescribed forms. In addition, a limit is placed on the number of context-free rules. More specifically, the first form has 2 + n context-free rules, where n is the number of terminals. Concerning non-context-free rules, each of them has the form AB -> CD, where A, B, C, D are nonterminals. The second normal form has always only two context-free rules---S -> S# and # -> e, where S is the start symbol, # is a nonterminal, and e is the empty string. Regarding non-context-free rules, each of them is of the form AB -> XD, where A, B, D are nonterminals and X is a nonterminal or a terminal.
@ARTICLE{FITPUB9949,
author = "Zbyn\v{e}k K\v{r}ivka and Alexander Meduna and Petr Zemek",
title = "Phrase-Structure Grammars: Normal Forms and Reduction",
pages = "1180--1185",
journal = "The Computer Journal",
volume = 59,
number = 8,
year = 2016,
ISSN = "0010-4620",
doi = "10.1093/comjnl/bxw001",
language = "english",
url = "https://www.fit.vut.cz/research/publication/9949"
}