TAILIEUCHUNG - Báo cáo khoa học: "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 attributes 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. . | A LOGICAL VERSION OF FUNCTIONAL GRAMMAR William c. Rounds University of Michigan Xerox PARC Alexis Manaster-Ramer IBM . Watson Research Center Wayne State University 1 Abstract 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 attributes 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. 2 Introduction Our basic approach to the problem of syntactic description is to use logical formulas to put conditions or constraints on ordering of constituents ancestor and descendant relations and feature attribute information in syntactic structures. The present version of our logic has predicates specifically designed for these purposes. A grammar can be considered as just a logical formula and the structures satisfying the formula are the syntactic structures for the sentences of the language. This notion goes back to DCG s 6 but our formulation is quite different. In particular it builds on the logic of Kasper and Rounds 3 a logic intended specifically to describe feature structures. The formulation has several new aspects. First it introduces the oriented feature structure as the primary syntactic structure. One can think of these structures as parse trees superimposed on directed graphs although the general definition allows much more flexibility. In fact our notation does away with the parse tree altogether. A second aspect of the notation is its treatment of word order. Our logic allows small grammars to define free-word order languages over large vocabularies in a way not possible with standard ID LP rules. It is not clear whether or not this treatment of word order was .

TỪ KHÓA LIÊN QUAN
TÀI LIỆU MỚI ĐĂNG
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.