Ordering default theories and nonmonotonic logic programs

作     者：Sakama, C 

作者机构：Wakayama Univ Dept Comp & Comun Sci Wakayama 6408510 Japan 

出 版 物：《THEORETICAL COMPUTER SCIENCE》 (理论计算机科学)

年 卷 期：2005年第338卷第1-3期

页      面：127-152页

核心收录：

学科分类：08[工学] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

主　　题：bilattice default logic logic programming multi-valued logic 

摘      要：First-order theories are ordered under logical entailment based on the amount of information derived from theories. In default logic, on the other hand, a theory contains default information as well as definite information. To order default theories, distinguishing different sorts of information is necessary to assess the information content of a default theory. For this purpose, we first introduce a multi-valued interpretation of default theories using a ten-valued bilattice. It distinguishes between definite and credulous/skeptical default information derived from a theory, and is used for ordering default theories based on their information contents. We then apply the technique to order nonmonotonic logic programs under the answer set semantics. The results of this paper provide a method for comparing default theories or nonmonotonic logic programs in a manner different from the conventional extension/model-based viewpoint. Moreover, they have important application to induction from nonmonotonic theories. (c) 2004 Elsevier B.V. All rights reserved.