 Central to Dung’s approach is the idea of an admissible set of arguments relative to an argument structure. A set of arguments \(A\) is admissible if and only if it is conflict free (no argument in \(A\) attacks another argument in \(A\)), and there is every argument that attacks something in \(A\) is itself attacked by something in \(A\). In other words, \(A\) can defeat everything that defeats one of its members. Dung’s approach incorporates the principle: “the one who laughs last, laughs best.”