LIRa Session: Atefeh Keshavarzi Zafarghandi

Speaker: Atefeh Keshavarzi Zafarghandi (University of Groningen)

Date and Time: Thursday, October 31st 2019, 16:30-18:00

Venue: ILLC Seminar Room F1.15, Science Park 107.

Title: Discussion Games for Preferred Semantics of Abstract Dialectical Frameworks.

Abstract. Argumentation has recently received increased attention within artificial intelligence. One widely used formalism is argumentation frameworks (AFs), defined in terms of the attack relation between arguments. One generalization of AFs is abstract dialectical frameworks (ADFs), which are expressive enough to model different types of logical relations among arguments. A fundamental issue in the context of argumentation formalisms is identifying which arguments are collectively accepted. Criteria used to settle argument acceptance are referred to as semantics. In ADF’s admissible semantics, interpretations do not contain unjustifiable information. Maximal admissible interpretations are called preferred interpretations. The current work introduces a discussion game as a proof method for preferred semantics of ADFs. 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, that is, the presented proof method is sound and complete with respect to preferred semantics.