On Supported Inference and Extension Selection in Abstract Argumentation Frameworks

We present two approaches for deriving more arguments from an abstract argumentation framework than the ones obtained using sceptical inference, that is often too cautious. The first approach consists in selecting only some of the extensions. We point out several choice criteria to achieve such a selection process. Choices are based either on the attack relation between extensions or on the support of the arguments in each extension. The second approach consists of the definition of a new inference policy, between sceptical and credulous inference, and based as well on the support of the arguments. We illustrate the two approaches on examples, study their properties, and formally compare their inferential powers.