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Re: Challenge for RDF Gurus :)

From: Seth Russell <seth@robustai.net>
Date: Thu, 14 Feb 2002 11:57:57 -0800
Message-ID: <00e301c1b591$e6750a80$657ba8c0@c1457248a.sttls1.wa.home.com>
To: <tarod@softhome.net>
Cc: <www-rdf-logic@w3.org>, <www-rdf-comments@w3.org>, <www-rdf-interest@w3.org>
From: <tarod@softhome.net>

> Seth Russell writes:
>
> > 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
>
>   Sorry, I meant both of them should be disjuntive.

Ok, I think I see what you meant.  Is this it?

http://robustai.net/mentography/rdfs_domain_range4.gif

But then wouldn't that would break one of the basic concepts of RDF grpahs
... all triples are anded together ?

Seth Russell
Received on Thursday, 14 February 2002 15:01:32 GMT

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