Explaining Non-monotonic Normative Reasoning using Argumentation Theory with Deontic Logic
This work addresses the need for legally sound explanations in design processes, particularly for autonomous systems, but it is incremental as it builds on an existing system.
The paper tackles the problem of providing designers with effective explanations for legally relevant design decisions by extending a previous reasoning system (LeSAC) with first-order deontic logic and preferences, and demonstrates its application in autonomous driving cases while proving it satisfies rationality postulates for coherent, legally valid explanations.
In our previous research, we provided a reasoning system (called LeSAC) based on argumentation theory to provide legal support to designers during the design process. Building on this, this paper explores how to provide designers with effective explanations for their legally relevant design decisions. We extend the previous system for providing explanations by specifying norms and the key legal or ethical principles for justifying actions in normative contexts. Considering that first-order logic has strong expressive power, in the current paper we adopt a first-order deontic logic system with deontic operators and preferences. We illustrate the advantages and necessity of introducing deontic logic and designing explanations under LeSAC by modelling two cases in the context of autonomous driving. In particular, this paper also discusses the requirements of the updated LeSAC to guarantee rationality, and proves that a well-defined LeSAC can satisfy the rationality postulate for rule-based argumentation frameworks. This ensures the system's ability to provide coherent, legally valid explanations for complex design decisions.