tailieunhanh - Báo cáo khoa học: "INCLUSION, DISJOINTNESS AND CHOICE: THE LOGIC OF LINGUISTIC CLASSIFICATION"

We investigate the logical structure of concepts generated by conjunction and disjunction over a monotonic multiple inheritance network where concept nodes represent linguistic categories and links indicate basic inclusion (ISA) and disjointhess (ISNOTA) relations. We model the distinction between primitive and defined concepts as well as between closed- and open-world reasoning. We apply our logical analysis to the sort inheritance and unification system of HPSG and also to classification in systemic choice systems. . | INCLUSION DISJOINTNESS AND CHOICE THE LOGIC OF LINGUISTIC CLASSIFICATION Bob Carpenter Computational Linguistics Program Philosophy Department Carnegie Mellon University Pittsburgh PA 15213 carp@ Carl Pollard Linguistics Department Ohio Sate University Columbus OH 43210 pollard@ Abstract We investigate the logical structure of concepts generated by conjunction and disjunction over a monotonic multiple inheritance network where concept nodes represent linguistic categories and links indicate basic inclusion isa and disjointness isnota relations. We model the distinction between primitive and defined concepts as well as between closed- and open-world reasoning. We apply our logical analysis to the sort inheritance and unification system of HPSG and also to classification in systemic choice systems. Introduction Our focus in this paper is a stripped-down monotonic inheritance-based knowledge representation system which can be applied directly to provide a clean declarative semantics for Halliday s systemic choice systems see Winograd 1983 Mel-lish 1988 Kress 1976 and the inheritance module of head-driven phrase-structure grammar HPSG Pollard and Sag 1987 Pollard in press . Our inheritance networks are constructed from only the most rudimentary primitives basic concepts and ISA and ISNOTA links. By applying general algebraic techniques we show how to generate a meet semilattice whose nodes correspond to consistent conjunctions of basic concepts and where meet corresponds to conjunction. We also show how to embed this result in a distributive lattice where the elements correspond to arbitrary conjunctions and disjunctions of basic concepts and where meet and join correspond to conjunction and disjunction respectively. While we do not consider either role- or attribute-based reasoning in this paper our constructions axe dữectly applicable as a front-end for the combined attribute-and concept-based formalisms of A it-Kaci 1986 .