Finite-state approximations of grammars
Fernando M. B. Pereira · 1990
Grammars for spoken language systems are subject to the conflicting requirements of language modeling for recognition and of language analysis for sentence interpretation. Current recognition algorithms can most directly use finite-state acceptor (FSA) language models. However, these models are inadequate for language interpretation, since they cannot express the relevant syntactic and semantic regularities. Augmented phrase structure grammar (APSG) formalisms, such as unification grammars, can express many of those regularities, but they are computationally less suitable for language modeling, because of the inherent cost of computing state transitions in APSG parsers.