Abstract
We propose a novel knowledge representation method for the Default Logic paradigm by developing a proof calculus that yields arguments and counterarguments in which defaults serve as explicit objects of reasoning. The proposed formalism allows for more transparent default reasoning and the use of explainability methods in formal argumentation. In particular, we provide a sound and complete argumentative characterization of Default Logic, by demonstrating that argumentation frameworks instantiated by the arguments derivable in our calculus yields the same inference relation as that of Default Logic. The modularity of our approach allows for various modifications of Default Logic. We demonstrate this by extending our calculus with a rule that enables disjunctive defeasible reasoning.
Kees van Berkel
Assistant Professor (Tenure Track)
My core research interests are in logical and argumentative perspectives on normative reasoning. This involves the investigation of problems in logic, AI, and philosophy. It includes the study of norm explanations in AI, the logical analysis of meta-ethical principles in deontic agency logics, prooftheoretic approaches for nonmonotonic normative reasoning, and argumentative characterizations of defeasible deontic logic.
Christian Straßer
Professor of Logic in Philosophy and Artificial Intelligence
Christian is a full professor of logic in philosophy and artificial intelligence at the Institute for Philosophy II, Ruhr University Bochum. He is an expert on nonmonotonic logic and logical argumentation. Among other things, he has been investigating nonmonotonic approaches to handling deontic conflicts, deontic detachment principles and proof theoretic approaches in deontic logic.