Synchronous context-free grammars and optimal linear parsing strategies
نویسندگان
چکیده
منابع مشابه
Synchronous Context-Free Grammars and Optimal Linear Parsing Strategies
Synchronous Context-Free Grammars (SCFGs), also known as syntax-directed translation schemata [AU69, AU72], are unlike context-free grammars in that they do not have a binary normal form. In general, parsing with SCFGs takes space and time polynomial in the length of the input strings, but with the degree of the polynomial depending on the permutations of the SCFG rules. We consider linear pars...
متن کاملSynchronous Context-Free Grammars and Optimal Parsing Strategies
The complexity of parsing with synchronous context-free grammars is polynomial in the sentence length for a fixed grammar, but the degree of the polynomial depends on the grammar. Specifically, the degree depends on the length of rules, the permutations represented by the rules, and the parsing strategy adopted to decompose the recognition of a rule into smaller steps. We address the problem of...
متن کاملOptimal Parsing Strategies for Linear Context-Free Rewriting Systems
Reduction is the operation of transforming a production in a Linear Context-Free Rewriting System (LCFRS) into two simpler productions by factoring out a subset of the nonterminals on the production’s righthand side. Reduction lowers the rank of a production but may increase its fan-out. We show how to apply reduction in order to minimize the parsing complexity of the resulting grammar, and stu...
متن کاملParsing Contextual Grammars with Linear, Regular and Context-Free Selectors
Contextual Grammars (CGs) provide an appropriate description of natural languages. Unfortunately, no parser which runs in polynomial time was known for some linguistically relevant classes. In this paper, an intertwined two–level Earley–based parser for CGs with finite, regular and context–free selectors is presented. In both phases context–free grammars are defined which identify individual se...
متن کاملParsing Beyond Context-Free Grammars
The first € price and the £ and $ price are net prices, subject to local VAT. Prices indicated with * include VAT for books; the €(D) includes 7% for Germany, the €(A) includes 10% for Austria. Prices indicated with ** include VAT for electronic products; 19% for Germany, 20% for Austria. All prices exclusive of carriage charges. Prices and other details are subject to change without notice. Al...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Computer and System Sciences
سال: 2015
ISSN: 0022-0000
DOI: 10.1016/j.jcss.2015.04.003