Reasoning about exceptions in ontologies: from the lexicographic closure to the skeptical closure

TL;DR

This paper introduces the skeptical closure, a new reasoning approach for handling exceptions in ontologies that extends the rational closure by allowing independent inheritance of defeasible properties.

Contribution

It proposes the skeptical closure, a variant of lexicographical closure, with a bi-preference semantics for better exception reasoning in description logics.

Findings

The skeptical closure enables independent inheritance of defeasible properties.

It provides a more nuanced reasoning mechanism than rational closure.

The bi-preference semantics characterizes the skeptical closure effectively.

Abstract

Reasoning about exceptions in ontologies is nowadays one of the challenges the description logics community is facing. The paper describes a preferential approach for dealing with exceptions in Description Logics, based on the rational closure. The rational closure has the merit of providing a simple and efficient approach for reasoning with exceptions, but it does not allow independent handling of the inheritance of different defeasible properties of concepts. In this work we outline a possible solution to this problem by introducing a variant of the lexicographical closure, that we call skeptical closure, which requires to construct a single base. We develop a bi-preference semantics semantics for defining a characterization of the skeptical closure.