BibTeX
@MISC{Lytinen_eft-cornerunification-base,
author = {Steven L. Lytinen and O Tomuro},
title = {eft-corner Unification-base},
year = {}
}
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Abstract
In this paper, we present an efficient algorithm for parsing natural language using unification grammars. The algorithm is an extension of left-corner parsing, a bottom-up algorithm which utilizes top-down expec-tations. The extension exploits unification grammar’s uniform representation of syntactic, semantic, and do-main knowledge, by incorporating all types of gram-matical knowledge into parser expectations. In par-ticular, we extend the notion of the reochcsbility ta-ble, which provides information as to whether or not a top-down expectation can be realized by a potential subconstituent, by including all types of grammatical information in table entries, rather than just phrase structure information. While our algorithm’s worst-case computational complexity is no better than that of many other algorithms, we present empirical test-ing in which average-case linear time performance is achieved. Our testing indicates this to be much im-proved average-case performance over previous left-corner techniques.
Keyphrases
eft-corner unification-base unification grammar bottom-up algorithm left-corner parsing efficient algorithm present empirical test-ing table entry natural language average-case linear time performance do-main knowledge many algorithm grammatical information structure information previous left-corner technique gram-matical knowledge potential subconstituent top-down expectation parser expectation top-down expec-tations unification grammar uniform representation much im-proved average-case performance algorithm worst-case computational complexity
