Uniquely Parsable Unification Grammars and Their Parser Implemented in Prolog
- 18 Downloads
A uniquely parsable grammar (UPG) introduced by Morita and coworkers is a formal grammar with a restricted type of rewriting rules, where parsing can be performed without backtracking. By extending a UPG, we introduce a uniquely parsable unification grammar (UPUG), and we investigate its applicability to parsing. A unification grammar (UG) is a system such that a sequence of terms is rewritten by a set of rules, and the rewriting process accompanies unification of terms as in Prolog. We first define a general framework of a UG and then give a UPUG-condition so that it has the property of unique parsability. Since the class of UPGs is a subclass of UPUGs and is known to be universal in language generating ability, the class of UPUGs is also universal. We then show a simple parsing method for UPUGs. Based on it, we give a Prolog implementation of a parser which will be useful for natural language analysis and other applications.
Unable to display preview. Download preview PDF.
- Deransart, P. and J. Maluszynski. A Grammatical View of Logic Programming, The MIT Press, Cambridge, MA, 1993.Google Scholar
- Knuth, D. E. On the translation of languages from left to right, Information and Control, 8: 607–639, 1965.Google Scholar
- Morita, K., N. Nishihara, Y. Yamamoto and Z. Zhang. A hierarchy of uniquely parsable grammar classes and deterministic acceptors, Acta Informatica, 34: 389–410, 1997.Google Scholar
- Pereira, F.C.N. and D.H.D. Warren. Definite clause grammar for language analysis, Artificial Intelligence, 13: 231–278, 1980.Google Scholar
- Rosenkrantz, D.J. and R. E. Stearns. Properties of deterministic top-down grammars, Information and Control, 17: 226–256, 1970.Google Scholar
- Sells, P. Lectures on Contemporary Syntactic Theories, CSLI Lecture Notes, Stanford, CA, 1985.Google Scholar