论文标题
三个值分离的混合MKNF知识库的固定点表征
A Fixpoint Characterization of Three-Valued Disjunctive Hybrid MKNF Knowledge Bases
论文作者
论文摘要
混合MKNF的逻辑(最少的知识和否定为失败)是一种有力的知识表示语言,它优雅地将ASP(答案集编程)与本体理学配对。析取规则是基于常规规则的推理的理想扩展,通常是为正常知识基础设计的语义框架,需要进行大量重组以支持脱节规则。另外,人们可以通过诱导普通知识基础的集合来提高正常规则的特征,以支持脱节规则,每个知识基地都具有相同的身体和一个原子。在这项工作中,我们将一组正常的知识基础称为脱节知识基础的头脑。是否可以使用带有切割的FixPoint构造来表征分离性混合MKNF知识库的语义是否出现问题。早些时候,我们已经表明,可以将头部切割与FixPoint运算符配对,以捕获分离的混合MKNF知识库的两值MKNF模型。三值语义扩展了两个值的语义,具有表达部分信息的能力。在这项工作中,我们提出了一个FixPoint构造,该构造使用操作员迭代地捕获具有分离规则的混合MKNF知识库的三个值模型。该特征还捕获了分离逻辑程序的部分稳定模型,因为程序可以表示为具有空的本体论的分离的混合MKNF知识库。我们详细介绍了正常混合MKNF知识库的船尾(近似固定点理论)之间的近似值之间的关系。
The logic of hybrid MKNF (minimal knowledge and negation as failure) is a powerful knowledge representation language that elegantly pairs ASP (answer set programming) with ontologies. Disjunctive rules are a desirable extension to normal rule-based reasoning and typically semantic frameworks designed for normal knowledge bases need substantial restructuring to support disjunctive rules. Alternatively, one may lift characterizations of normal rules to support disjunctive rules by inducing a collection of normal knowledge bases, each with the same body and a single atom in its head. In this work, we refer to a set of such normal knowledge bases as a head-cut of a disjunctive knowledge base. The question arises as to whether the semantics of disjunctive hybrid MKNF knowledge bases can be characterized using fixpoint constructions with head-cuts. Earlier, we have shown that head-cuts can be paired with fixpoint operators to capture the two-valued MKNF models of disjunctive hybrid MKNF knowledge bases. Three-valued semantics extends two-valued semantics with the ability to express partial information. In this work, we present a fixpoint construction that leverages head-cuts using an operator that iteratively captures three-valued models of hybrid MKNF knowledge bases with disjunctive rules. This characterization also captures partial stable models of disjunctive logic programs since a program can be expressed as a disjunctive hybrid MKNF knowledge base with an empty ontology. We elaborate on a relationship between this characterization and approximators in AFT (approximation fixpoint theory) for normal hybrid MKNF knowledge bases.