Prioritized Norms in Formal Argumentation
This work addresses a theoretical problem in formal argumentation and normative reasoning, but it appears incremental as it builds on existing hierarchical abstract normative systems.
The paper tackles the problem of representing prioritized normative reasoning in formal argumentation by proposing three approaches (Greedy, Reduction, Optimization) and showing how they can be implemented using argumentation principles like weakest link and last link.
To resolve conflicts among norms, various nonmonotonic formalisms can be used to perform prioritized normative reasoning. Meanwhile, formal argumentation provides a way to represent nonmonotonic logics. In this paper, we propose a representation of prioritized normative reasoning by argumentation. Using hierarchical abstract normative systems, we define three kinds of prioritized normative reasoning approaches, called Greedy, Reduction, and Optimization. Then, after formulating an argumentation theory for a hierarchical abstract normative system, we show that for a totally ordered hierarchical abstract normative system, Greedy and Reduction can be represented in argumentation by applying the weakest link and the last link principles respectively, and Optimization can be represented by introducing additional defeats capturing the idea that for each argument that contains a norm not belonging to the maximal obeyable set then this argument should be rejected.