Computing Extensions of Abstract Argumentation Frameworks by Enumerating Closed Sets

We present a new approach for computing complete, stable and preferred extensions of abstract argumentation frameworks. Unlike existing approaches that reduce these problems to the propositional satisfiability problem and solve them with the help of SAT-solvers, our approach solves them directly by making use of the fact that the mentioned extensions are contained in certain closure systems. Our algorithms enumerate these closed sets and filter the searched extensions. Experimental results show that our approach outperforms the existing approaches for a large number of the test cases.