Specification and Complexity of Strategic-Based Reasoning Using Argumentation

In this paper, we propose a new strategic and tactic reasoning for agent communication. This reasoning framework is specified using argumentation theory combined to a relevance theory. Strategic reasoning enables agents to decide about the global communication plan in terms of the macro-actions to perform in order to achieve the main conversational goal. Tactic reasoning, on the other hand, allows agents to locally select, at each moment, the most appropriate argument according to the adopted strategy. Previous efforts at defining and formalizing strategies for argumentative agents have often neglected the tactic level and the relation between strategic and tactic levels. In this paper, we propose a formal framework for strategic and tactic reasoning for rational communicating agents and the relation between these two kinds of reasoning. Furthermore, we address the computational complexity of this framework and we argue that this complexity is in the same level of the polynomial hierarchy than the complexity of the strategic-free argumentation reasoning.