AGM Meets Abstract Argumentation: Expansion and Revision for Dung Frameworks∗

In this paper we combine two of the most important areas of knowledge representation, namely belief revision and (abstract) argumentation. More pre-cisely, we show how AGM-style expansion and re-argumentation frameworks (AFs). Our approach is based on a reformulation of the original AGM postulates for revision in terms of monotonic conse-quence relations for AFs. The latter are defined via a new family of logics, called Dung logics, which satisfy the important property that ordinary equiva-lence in these logics coincides with strong equiva-lence for the respective argumentation semantics. Based on these logics we define expansion as usual via intersection of models. We show the existence of such operators. This is far from trivial and re-quires to study realizability in the context of Dung logics. We then study revision operators. We show why standard approaches based on a distance mea-sure on models do not work for AFs and present an operator satisfying all postulates for a specific Dung logic.