  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.
