Expanding argumentation frameworks: Enforcing and monotonicity results

Abstract. This paper addresses the problem of revising a Dung-style argumentation framework by adding finitely many new arguments which may interact with old ones. We study the behavior of the extensions of an argumentation framework if we extend it (new information) and/or change the underlying semantics (change of proof standards). We show both possibility and impossibility results related to the problem of enforcing a desired set of arguments. Furthermore we will prove some monotonicity results for a special class of expansions with respect to the cardinality of the set of extensions and the justification state