Long answer: When atfinity evaluates rules, it predominantly takes the instances within a case into account. The information keys within an instance are a combination of the ontology of the instance and all its assigned roles. This means there is usually no problem if different ontologies would have the same information keys, e.g. Entity.name and Person.name, but problems arise when a role has the same information, e.g. Father.name and Husband.name. If now an instance peter is both a father and a husband, it becomes unclear to atfinity what you mean by peter.name.