$\mathcal{ALE}$ Defeasible Description Logic [chapter]

Pakornpong Pothipruk, Guido Governatori
2006 Lecture Notes in Computer Science  
One of Semantic Web strengths is the ability to address incomplete knowledge. However, at present, it cannot handle incomplete knowledge directly. Also, it cannot handle non-monotonic reasoning. In this paper, we extend ALC − Defeasible Description Logic with existential quantifier, i.e., ALE Defeasible Description Logic. Also, we modify some parts of the logic, resulting in an increasing efficiency in its reasoning. Introduction Description logics, which is a language based on first order
more » ... , cannot handle incomplete and inconsistent knowledge well. In fact, it is often that complete and consistent information or knowledge are very hard to obtain. Consequently, there is an urgent need to extend description logics with a non-monotonic part which can handle incomplete and inconsistent knowledge better than themselves. Defeasible logic, developed by Nute [6], is a well-established nonmonotonic reasoning system. Its outstanding properties are low computational complexity [4, 5] and ease of implementation. Thus, this logic is the nonmonotonic part of our choice. Governatori [3] proposes a formalism to extend ALC − with defeasibility. He combines the description logic formalism with the defeasible logic formalism, creating a logic that can handle both monotonic and nonmonotonic information coherently. We extend this work to be able to handle existential quantification.
doi:10.1007/11941439_15 fatcat:6u5upuwt6bfslmbe3iqowtw5vm