Modelling Value-oriented Legal Reasoning in LogiKEy

TL;DR

This paper demonstrates how the LogiKEy framework can model, formalize, and verify legal reasoning involving value preferences, using theorem proving to analyze property law cases within a formal logic system.

Contribution

It introduces a novel application of LogiKEy to legal reasoning, integrating non-classical logics and automated theorem proving for legal domain modeling.

Findings

Successfully formalized property law cases involving value preferences.

Demonstrated the use of Isabelle proof assistant for legal reasoning.

Established connections between non-classical logics and legal knowledge representation.

Abstract

The logico-pluralist LogiKEy knowledge engineering methodology and framework is applied to the modelling of a theory of legal balancing in which legal knowledge (cases and laws) is encoded by utilising context-dependent value preferences. The theory obtained is then used to formalise, automatically evaluate, and reconstruct illustrative property law cases (involving appropriation of wild animals) within the Isabelle proof assistant system, illustrating how LogiKEy can harness interactive and automated theorem proving technology to provide a testbed for the development and formal verification of legal domain-specific languages and theories. Modelling value-oriented legal reasoning in that framework, we establish novel bridges between latest research in knowledge representation and reasoning in non-classical logics, automated theorem proving, and applications in legal reasoning.