Re: rdfs:subClassOf and metaclasses

At 10:41 01/07/2002 -0700, Piotr Kaminski wrote:
[...]

>I see (at least) 3 possible answers:
>
>1.  That's your problem, not RDFS'.

I think that's the answer.  RDFS has no notion of meta class.  You are 
building that.

>   If you put enough constraints on the M2
>metaclasses, any M1 class that tries to be an instance of some unrelated
>bunch of them won't be able to have any M0 instances anyway.
>
>2.  You shouldn't use rdfs:subClassOf for subclasses of rdfs:Class.

I've done this and found it useful in a real application.  The classes I 
defined were not metaclasses, I just wanted to restrict the range (or 
domain, I can't remember) to one of a set of classes.

>Introduce your own subproperty of it, and restrict it to pairs of matching
>metaclasses.
>
>3.  Introduce a rule into RDFS prohibiting the situation above:

My take is that this going beyond what RDFS is trying to do.  Others may 
disagree.  Danbri, Guha?

Brian