Independent Transfer Using Graph Unification

We present a MT system that applies graph unification in transfer from English to Finnish. The work described below is an outgrowth of a multilingual MT project initiated by the IBM in 1987 with the aim of studying multilingual translation using a common English language parser. The transfer system presented here is independent of the parsing and generation modules. Any source language parser can be used whose output can be expressed in a directed graph form. The transfer system is responsible for generating target language phrase structure. Target language word order and morphology are left to the generation modules. The transfer system is lexically based. Transfer rules, presented in the form of bilingual graphs, are declarative statements of symmetric transfer relationships between words, phrases or constructions in the two intertranslatable languages. Transfer is structure driven in that the transfer algorithm traverses the source language graph, nondeterministically trying to apply the relevant transfer rules in the lexicon. Each successful transfer yields a bilingual graph, whose target hmguage half is extracted and subjected to linearization and morphological generation. The main f(ycus of attention in our project is the development of the lexicon subsystem. The lexicon system consisk~ of separate transfer and monolingual lexicons and a common lexicon of language independent definitions.