Although various aspects of soft-constraint based norms have been explored, it is still challenging to understand preemption. Preemption is a situation where higher-level norms override lower-level norms when new information emerges. To address this, we propose a derivation state argumentation framework (DSA-framework). DSA-framework incorporates derivation states to explain how preemption arises based on evolving situational knowledge. Based on DSA-framework, we present an argumentative approach for explaining preemption. We formally prove that, under local optimality, DSA-framework can provide explanations why one consequence is obligatory or forbidden by soft-constraint based norms represented as logical constraint hierarchies.

翻译：尽管软约束规范的各个方面已得到广泛研究，但理解优先权仍具挑战性。优先权是指当新信息出现时，高层级规范覆盖低层级规范的情形。为此，我们提出一种推导状态论证框架（DSA框架）。该框架通过引入推导状态，基于演化的情境知识解释优先权的产生机制。基于DSA框架，我们提出一种用于解释优先权的论证方法。我们形式化证明：在局部最优性条件下，对于表示为逻辑约束层次结构的软约束规范，DSA框架能够解释特定后果为何被判定为义务性或禁止性。