Discussion Games for Preferred Semantics of Abstract Dialectical Frameworks

Abstract dialectical frameworks (ADFs) are introduced as a general formalism for modeling and evaluating argumentation. However, the role of discussion in reasoning in ADFs has not been clarified well so far. The current work provides a discussion game as a proof method for preferred semantics of ADFs to cover this gap. We show that an argument is credulously acceptable (deniable) by an ADF under preferred semantics iff there exists a discussion game that can defend the acceptance (denial) of the argument in question.