A Logical Version of Functional Grammar

Kay's functional-unification grammar notation [5] is a way of expressing grammars which relies on very few primitive notions. The primary syntactic structure is the feature structure, which can be visualised as a directed graph with arcs labeled by at t r ibutes of a constituent, and the primary structure-building operation is unification. In this paper we propose a mathematical formulation of FUG, using logic to give a precise account of the strings and the structures defined by any grammar written in this notation.