Argumentation is the interdisciplinary study of how conclusions can be reached through the construction and evaluation of arguments, that is, structures describing a proposition together with the reasons for accepting it. The field has received growing interest within Artificial Intelligence over the last decades. It covers aspects of knowledge representation and multi-agent systems, but also touches on various philosophical questions. Phan Minh Dung's abstract argumentation frameworks (AFs) play a dominant role in the field. In AFs arguments and attacks among them are treated as primitives,...