[abraxaz]

Given that OWL and RDF is meant for both open world data and data models, and is amenable to partial specification, it really solves the problem of relating legal rules to the rest of the world quite well. In your legal ontology you just specify evidence, and admissible evidence, and then another ontology can pick up from there and model it in a specific domain.

And OWL has formal and provable entailment rules. So everyone can agree, given samme ontologies what the implications are. There are unsolved problems there but most of the things you list are already thought through.