Attack Relations among Dynamic Coalitions

In this paper we introduce a formal argumentation framework to reason b ut the evolution of coalitions. We extend Amgoud’s preference-based argumentation framework f or coalition formation to an argumentation framework with nested attack relations along the lines proposed by Mod gil, and we define an instance of the argumentation framework for reasoning about coalitions b ased on a new dynamic extension of Conte and Sichman’s static dependence networks. We show how this ne w approach covers a wider range of attacks than Amgoud’s task based coalition formation, including a ttacks weakening the stability of the coalition by removing dependencies. Moreover, we show how it ca n be used not only for coalition formation, but also for coalitions which evolve due to the addition of depend encies.