Accession Number : ADP001168

Title :   Parsing with Logical Variables,

Corporate Author : MOORE SCHOOL OF ELECTRICAL ENGINEERING PHILADELPHIA PA DEPT OF COMPUTER AND INFORMATION SCIENCES

Personal Author(s) : Finin,Timothy W. ; Palmer,Martha Stone

Report Date : 01 FEB 1983

Pagination or Media Count : 7

Abstract : Logic based programming systems have enjoyed an increasing popularity in applied AI work in the last few years. One of the contributions to Computational Linguistics made by the Logic Programming Paradigm has been the Definite Clause Grammar. In comparing DCG's with previous parsing mechanisms such as ATN's, certain clear advantages are seen. We feel that the most important of these advantages are due to the use of Logical Variables with Unification as the fundamental operation on them. To illustrate the power of the Logical Variable, we have implemented an experimental ATN system which treats ATN registers as Logical Variables and provides a unification operation over them. We would like to simultaneously encourage the use of the powerful mechanisms available in DCG's, and demonstrate that some of these techniques can be captured without reference to a resolution theorem prover.

Descriptors :   *Parsers, *Computer logic, *Computational linguistics, *Computer programming, Symposia, Artificial intelligence, Variables, Phrase structure grammars, Context free grammars, Augmentation, Transitions, Networks, Transformational grammars, Natural language, Programming languages

Distribution Statement : APPROVED FOR PUBLIC RELEASE