Hi Victor,
Meanwhile I've to say that we don't need sandbox namespaces for dm: and tm:, we've to use standardized URIs to ease work with our definitions.
[HT] There are no standardized URIs yet. Any time someone does some work he comes up with yet another URI. We tried to get this done in JORD, but so far without success. That's why I suggested some easy to remember, short URIs as a proposal for standardization.
First of all, I don't like the use of Powerset term in this context (and in that discussion). It is because of "if and only if" clause. Let's consider PUMP TYPE ClassOfClassOfIndividual. If you call it a powerset of PUMP ClassOfIndividual, then you are implying that _any_ subset of pumps is worth to be called "pump type". Rather strong assumption, no? The same problem you can see at type level, though it is more difficult to make an obviously wrong examples at an abstract level.
[HT] I don't know which document you were looking at, but the one I sent does not have PUMP TYPE listed.
I'm suggesting to declare sameAs where you are declaring equivalentClass.
[HT] owl:sameAs is for individuals (the OWL individuals). I quote from W3C:
The built-in OWL property owl:sameAs links an individual to an individual. Such an owl:sameAs statement indicates that two URI references actually refer to the same thing: the individuals have the same "identity".
The ability to express equivalences using owl:sameAs can be used to state that seemingly different individuals are actually the same. Real class equality or property equality can only be expressed with the owl:sameAs construct. As this requires treating classes and properties as individuals, such axioms are only allowed in OWL Full.
For equivalentClass I quote from W3C:
owl:equivalentClass is a built-in property that links a class description to another class description. The meaning of such a class axiom is that the two class descriptions involved have the same class extension (i.e., both class extensions contain exactly the same set of individuals).
But there are OWLgeeks that have another opinion.
But the first and foremost objection is simple - we don't need A and B classes in reference data if we have equivalent data model classes already.
[HT] The OWLgeeks that work on 15926-in-OWL are not in agreement with you. They think in terms of power sets (I am not that clever). They consider the Part 2 entity types as a kind of meta classes. As such I can live with that.
Do you remember the discussion we recently had about complex entity types? You can only build those in reference data, and in order to do that you have to create a union of two reference classes that are members of those power sets (alias Part 2 entity types).
Regards,
Hans