To fully u n d e r s t a n d a sequence of utterances, one must be able to infer implicit relationships b e t w e e n the utterances. A l t h o u g h the identification of sets of utterance relationships forms the basis for many theories of discourse, the f o r m a l i z a t i o n and recognition of such relationships has p r o v e n to be an e x t r e m e l y difficult c o m.