QUIXOTE as a tool for natural language processing

Abstract

We developed a language QUZXOTS as a tool to deal with various information of natnral language processing (NLP). QUZXOTE is a hybrid language of deductive object-oriented database (DOOD) aiid constraint logic programming (CLP) language. The new niechaiiisiii of QUTXOTC is a coiiibiiiatioii of an objectorieiitatioii coiicept such as object zdentity and the concept of module that classifies a large knowledge base. In addition, its logical inference system is extended to be able to make restricted abduction. We first apply QUZXOTE to the sorted feature structure of constraint-based grammar forinalisins. Next, we show that QUTXOTE can contribute to the description of situation-based semantics. We iinpleiiiented a systein to make abductive reasoning to clarify hidden information. Also we resolve the probleiii of iiouii phrase reference. Basic Structure of QUZXOTE141 as a tool for NLP. QUZXOTC is classified as both a DOOD and CLP language. It has the followiiig features that are also useful in NLP: 0 00 features, such as object identity, 0 attribntc-valiie data st,riictiirc with siibsiuiiption cfficieiit iiiforiiiatioii clcscriptioii with iiiodules 0 question and answer with assumptions.constrailits, i~lltl iiilicritaiicc hi(!riLrchy. itlltl QUZXOTS system is inipleineiited with tlie KL1 laiiguage, a parallel logic prograniiniiig language for the parallel inference machine, PIM, in ICOT.Generally, QUTXOTE programs consist of subsumption relations among basic object teriiis (l.l), snbmodule relations among modules (1.3), aiid rules. QUZXOTC rules have the following syntax. head head-constraant body body-constraznt ---r c c -\ 7120 :: H I HC -+=mi : l31,-.. BC ;;Here. H and B, are object/attribute t e r m . HC and BC are constraints. nz,, called a module irlentifiei;specifies tlie iiiodiile in which terms or rules resides. The body. constraint, ailcl inodule ideiitifier can be omitted.The above rule resides in module mo. It implies that, if every B, holds in a module nz, uiider constraints B C , then H a i d colistrailits HC hold in 1720. Object TermLet Obj,Bobj,Cobj, and V a r be a collection of object t e r m . basic object terms, complex object terns. a d vn~anbles, respectively. Then. Obj = Bobj U Cobj U Var.Basic object terms are atomic symbols siich as c a t aiid apple.Subsumption rekition E, is a partial order relation between basic object terms. a b iiieaiis that a is niore specific tliaii b, or a ISA b, for exaniple, c a t & animal or animal 5 creature. Special basic object teriiis I aiid T satisfy Vx E Bobj; I 5 X , x 5 T. QUZXOTC coinprises a complete lattice from < Bobj. E>.A complex object t m r i is a term having the forin Bohj. ' t i ; E Ohj. Each label 1 , is cz1lt:d ai1 in,tl-insic attl-ibute. The order of labels is not significant, so o Cl=a ,m=bl and o Cm=b, 1=al, for example, are identical. The subsumption relation is extended to treat coinplex object terms. For example, when c a t & animal, cat[age = 2, sex = male] E cat[age = 21 cat[color = white] E animal.