Three-valued logic for reasoning from an inconsistent knowledge base
✍ Scribed by Ikuo Tahara; Shiho Nobesawa
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 271 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0882-1666
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Nontrivial reasoning under inconsistency, called paraconsistent reasoning, has been discussed mainly in two frameworks; one is the classical logic (consistency‐based) framework and the other is the three‐valued logic framework. In this paper, we propose a new entailment relation based on three‐valued logic for reasoning from an inconsistent knowledge base, and discuss the relation between the previous two frameworks. A U‐minimum model of the inconsistent knowledge base is defined in accordance with a principle of uncertainty minimization for three‐valued models. We show that every set of atomic formulas assigned the additional third value in the U‐minimum model is the minimum hitting set for the collection of sets each of which consists of atomic formulas occurring in the minimal inconsistent set of the knowledge base. Based on this result, we present an algorithm to compute the paraconsistent entailment relation by reducing the three‐valued entailment relation to a two‐valued classical entailment relation. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(14): 44–51, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20539