作者: Stanley R. Petrick
DOI: 10.1016/B978-0-12-404970-3.50019-7
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摘要: Publisher Summary The TQA System, formerly called the REQUEST is an experimental transformational-grammar-based English question-answering system suitable for interfacing with large relational data bases. parser started out fully general. Its principal early extension was to allow binary features on nonterminal and terminal nodes make transformations sensitive capable of altering those features. To deal full trees at each transformational step, a surface structure CF grammar derived constituent grammar, both potential slack, were used. Forward continued be written invoked, but style in writing not introduce slack inverse then eliminate that forward transformations, rather true inverses their counterparts. Building deep structures from top sentence embedding levels down reminiscent analysis, constitutes portion basis often made claim it possible perform analysis by means augmented transition network.