Abstract. Abstract argumentation frameworks have played a major role as a way of understanding argument-based inference, resulting in different argument-based proof procedures. We will provide an abstract characterization of the warrant construction in the context of Skeptical Argumentation Frameworks. Often in the literature an argument is regarded as an explanation as well as a form of support for a claim, and this argument is evaluated to decide if the claim is accepted. The concept of explanation has received attention from different areas in Artificial Intelligence, particulary in the Knowledge-Based Systems community. Only a few of them consider explanations in relation with argument systems. In this paper, we propose a type of explanation that attempts to fill this gap providing a perspective from the point of view of argumentation systems. 1

This article falls within the field of abstract argumentation frameworks. In particular, we focus on the study of frameworks using a proof procedure based on dialectical trees. These trees rely on a marking procedure to determine the warrant status of their root argument. Thus, our objective is to formulate rationality postulates to characterize the marking criterion over dialectical trees. The behavior of the marking procedure is closely tied to the alteration of trees, which is the keystone of any model of change based on dialectical argumentation. Hence, the results achieved in this work will benefit research on dynamics in argumentation. 1

This paper discusses a process of argumentation. We propose an algorithm for dynamic treatment of argumentation in which all lines of argumentation are executed in succession, and the agent’s knowledge base can change during argumentation. We show that there exists a case in which an agent dynamically loses argumentation that would be considered won by a static analysis. We also show that the algorithm terminates, and describe acceptable arguments that are obtained after the argumentation. 1