What Is a Skeptical Proof?

Abstract. We investigate the task of skeptically reasoning in extensionbased, nonmonotonic logics by concentrating on general argumentation theories. The restricted applicability of Dung’s notion of skeptical provability in his well-known argumentation framework is illustrated, and a new approach based on the notion of a claim associated with each argument is proposed. We provide a formal definition of a skeptical proof in our framework. As a concrete formalism, default logic in case of normal default theories is embedded in the general framework. We prove a formal correspondence between the two notions of skeptical provability, which enables us to adopt the general concept of a skeptical proof into default logic.

• Type: Conference
• Year: 1995
• Where: KI
• Authors: Michael Thielscher
• Keywords: Artificial Intelligence, Default Logic, KI 1995, Skeptical Proof, Skeptical Provability