Re: Challenge for RDF Gurus :)

From: <tarod@softhome.net>

> > re: http://robustai.net/mentography/rdfs_domain_range2.gif
> >
> >
> > >   Good try but I must say that it's not 100% what I asked for because
for
> > > the range issue you use
> > >   Class C
> > >   A is subClassOf C
> > >   B is subClassOf C
> > >   And then c range is C. It's a good aproach but it's not logically
> > > correct, you are saying that range of c is (C or A or B) and I asked
for
> > > range of c should be (A or B)
> >
> > Ok, I saw this problem after I published the graph.  I would need a way
to
> > say that there is no instances of C which is not and instance of A or B.
> > I'm beginning to agree with Sean, there is no way to say this with the
> > primitives of rdfs only.
>   It was posible before some RDFCore changes :)
>
> > What is your objection to using the daml schema?
>
>   I have no objection, this is just a challenge.
>
> > >   Now try it with the old aproach it's easier.
> >
> > What approach are you talking about here?
>
>   Before some changes in the schema, that a property had two domains (at
> the begining a property must only have one range, now it can have more
than
> one) means that the subject of the property must be in one of those
> domains, it was a disjuntion of restrictions. When they added more than
one
> range if they had used this vision, the value of a property must be a
> member of one of the domains, if that make sense to you, try it now. It's
> very easy having this in mind.

Well if the domain restraint is jisunctive and the range restraint is
conjunctive, then I suppose your example would eaisly work that old way.
But if one wanted the opposite case ( range (A and B).  domain ( A or B)),
then we still couldn't do it.   Intiitively don't we want domain and range
to be symmetric here?

Mentograph available upon request.
Seth Russell

Received on Thursday, 14 February 2002 13:57:11 UTC