W3C home > Mailing lists > Public > www-rdf-interest@w3.org > February 2002

Re: Challenge for RDF Gurus :)

From: Seth Russell <seth@robustai.net>
Date: Thu, 14 Feb 2002 10:53:37 -0800
Message-ID: <00bd01c1b588$e95c3b00$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>

> > 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
> > > 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
> > > range of c should be (A or B)
> >
> > Ok, I saw this problem after I published the graph.  I would need a way
> > 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
> 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
> 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 13:57:12 UTC

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