Conceptual Basis of the Lexicon in Machine Translation

This report describes the organization and content of lexical information required for the task of machine translation. In particular, the lexical- conceptual basis for UNITRAN, an implemented machine translation system, will be described. UNITRAN uses an underlying form called {\it lexical conceptual structure} to perform {\it lexical selection\/} and {\it syntactic realization\/}. Lexical word entries have two levels of description: the first is an underlying lexical-semantic representation that is derived from hierarchically organized primitives, and the second is a mapping from this representation to a corresponding syntactic structure. The interaction of these two levels will be discussed and the lexical selection and syntactic realization processes will be described.