Using AllDifferent in OWL Ontology defintion

Question

Hello,

Can I someone explain what is meant by 'OWL does not have a unique name assumption. Just because two names are different does not mean they refer to different individuals'.

Does that mean that every time I declare some individuals belonging to a class I should state that they are all different?

Thanks

Answer 1

An ontology which makes the unique name assumption (UNA) implicitly treats all entities as distinct. If the ontology does not enforce UNA, then it is possible for two concepts with different names to be inferred to be equivalent.

OWL does not make the UNA assumption. Therefore, if you have a class whose members are truly distinct, and you want to model that, then you need to explicitly declare it, either with differentFrom or AllDifferent. This is exactly what is done in the example of the three distinct wines in the Owl Language Guide.