Motivated by its applicability on deliberative inteligent agents, this work introduces the problem of finding what facts should be incorporated to a DeLP program in order to change the state of warrant of a particular literal. To achieve a deeper understanding of this problem, we analize how the incorporation of a specific set of facts affects the warrant of a particular literal. Finally, we introduce a formula that formally expresses how a topological change in a dialectical tree affects the status of the argument on its root.