Dynamic Epistemic Reasoning with Awareness and Its Legal Application

Abstract

Concerning a software tool of legal reasoning, it is important to describe the prediction about the result of a criminal action, because a crime is often caused by the unpredictability of the result of the defendant. In the court, the judge needs to investigate the predictability and the intention of the agent. Previously, we have formalized the reasoning process of judgment by action model in dynamic epistemic logic (DEL) and have attempted to describe the precedents. However, the prediction in legal cases depends not only on the states of knowledge but also on the limited degree of attention by agents. In this paper, we employ DEL with awareness for multi-agent to represent the predictability and model the typical criminal precedents. We propose a revised semantics of action model with awareness which can define each basic action model to reproduce the agent’s considering process. To describe the legal reasoning we introduce an extension of modeling program DEMO to include the awareness (we call it DEMO+𝒜) and present a GUI in this extended program to calculate the updated epistemic model easily and to classify precedents according to the degree of prediction. In the end, we calculate the epistemic models of typical criminal precedents by this newly developed tool and estimate them.

Keywords

• Dynamic epistemic logic
• action model
• model checking
• awareness
• legal reasoning