Bipolar Argumentation Frameworks with Specialized Supports

We generalize in this paper the Dung´s abstract argumentation theory in order to represent, in addition to the attack relation, a particular kind of support relation which captures knowledge of the form : “argument a is necessary to obtain argument b”. Unlike a general unspecified support, the necessity relation has the advantage to ensure that its interaction with direct attacks generates new (indirect) attacks having exactly the same nature of the direct ones. We discuss the advantageous consequences of this specialization of the support relation on the acceptability semantics of the underlying bipolar framework. Then, we show a suitable translation of any such bipolar framework into a logic program without passing by a preliminary translation into the classical framework of Dung.