Unification-Based Semantic Interpretation in the BBN Spoken Language System

This paper describes the current state of work on unification-based semantic interpretation in HARC (for Hear and Recognize Continous speech) the BBN Spoken Language System. It presents the implementation of an integrated syntax/semantics grammar written in a unification formalism similar to Definite Clause Grammar. This formalism is described, and its use in solving a number of semantic interpretation problems is shown. These include, among others, the encoding of semantic selectional restrictions and the representation of relational nouns and their modifiers.