An Efficient Algorithm for Admissible Argumentation Stages

In this paper we introduce AASExts, an algorithm for computing admissible argumentation stage extensions—a.k.a. semi–stable extensions. Admissible argumentation stage extensions play a decisive role in unifying two lines of research in formal argumentation: admissible-based extensions as suggested by Dung in his seminar paper; and the traditional approach based on dialectical evaluation of the defeat status of arguments. In this paper, we improve techniques developed for other semantics, notably preferred semantics, as well as leverage—for the first time—recent advances in All-SAT community. We prove our proposed algorithm is sound and complete, and we show empirically that our implementation significantly outperforms even sophisticated ASP-based and SAT-based reduction approaches on existing benchmarks.