Strong and Weak Forms of Abstract Argument Defense

Extended abstract frameworks separate conflicts and preference between arguments. These elements are combined to induce argument defeat relations. A proper defeat is consequence of preferring an argument in a conflicting pair, while blocking defeat is consequence of incomparable or equivalent-in-strength conflicting arguments. As arguments interact with different strengths, the quality of several argument extensions may be measured in a particular semantics. In this paper we analyze the strength of defenses in extended argumentation frameworks, under admissibility semantics. A more flexible form of acceptability is defined leading to a credulous position of acceptance.