  Gemini is a natural language understanding system developed for spoken
language applications. The paper describes the architecture of Gemini, paying
particular attention to resolving the tension between robustness and
overgeneration. Gemini features a broad-coverage unification-based grammar of
English, fully interleaved syntactic and semantic processing in an all-paths,
bottom-up parser, and an utterance-level parser to find interpretations of
sentences that might not be analyzable as complete sentences. Gemini also
includes novel components for recognizing and correcting grammatical
disfluencies, and for doing parse preferences. This paper presents a
component-by-component view of Gemini, providing detailed relevant measurements
of size, efficiency, and performance.
