Incorporating Stage Semantics in the SCC-recursive Schema for Argumentation Semantics

Recently, the stage and cf2 semantics for abstract argumentation attracted specific attention. By distancing from the notion of defense, they are capable to select arguments out of odd-length cycles. Furthermore, the maximality criterion of naive sets ensures reasonable solutions. The SCCrecursive schema, where the cf2 semantics is defined in, guarantees that some specific evaluation criteria, like directionality, weakand CF-reinstatement, are fulfilled. Beside several desirable properties, both stage and cf2 semantics still have some drawbacks. The stage semantics does not satisfy the above mentioned evaluation criteria, whereas cf2 semantics produces some questionable results on frameworks with cycles of length≥ 6. That’s why we suggest to combine stage semantics with the SCC-recursive schema of cf2 semantics. The resulting stage2 semantics overcomes the problems regarding cf2 semantics and still fulfills the mentioned evaluation criteria. Furthermore, we analyze redundant patterns for stage2 semantics, and we provide a complexity analysis of the associated reasoning problems.