首页 | 本学科首页   官方微博 | 高级检索  
     


Inferring negative information from disjunctive databases
Authors:Kenneth A. Ross  Rodney W. Topor
Affiliation:(1) Department of Computer Science, University of Melbourne, 3052 Parkville, Victoria, Australia;(2) Present address: Department of Computer Science, Stanford University, 94305 Stanford, CA, U.S.A.
Abstract:We propose criteria that any rule for inferring negative information from disjunctive databases should satisfy, and examine existing rules from this viewpoint. We then present a new inference rule, the ‘disjunctive database rule’ (DDR), and compare it to the existing rules with respect to the criteria. In particular, the DDR is equivalent to the CWA for definite databases, it infers no more negative information than the GCWA, and it interprets disjunction inclusively rather than exclusively. We generalize the DDR to a class of layered databases, describe an implementation of the DDR, ‘negation as positive failure’, and study its soundness and completeness properties.
Keywords:Deductive database  disjunctive database  indefinite  database  inference  negation  closed world assumption
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号