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Re: Subjects as Literals

From: Paul Gearon <gearon@ieee.org>
Date: Fri, 2 Jul 2010 05:27:04 -0700
Message-ID: <AANLkTim5wHWHHuLa7EtD3enS99IKa-oc48DGP9ADMJQ9@mail.gmail.com>
To: Reto Bachmann-Gmuer <reto.bachmann@trialox.org>
Cc: Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
On Fri, Jul 2, 2010 at 2:16 AM, Reto Bachmann-Gmuer
<reto.bachmann@trialox.org> wrote:
> Serialization formats could support
>
> "Jo" :nameOf :Jo
>
> as a shortcut for
>
> [ owl:sameAs "Jo"; :nameOf :Jo]
>
> and a store could (internally) store the latter as
>
> "Jo" :nameOf :Jo
>
> for compactness and efficiency.

While this may be possible, you've promoted owl:sameAs to have a true
semantic relationship at this level. You're treating it as if it
really does mean "equals". Given your scenario, I'd expect:

[ owl:sameAs "foo", "bar" ]

to lead to the following being stored:

"foo" owl:sameAs "bar"

Since we only got here because owl:sameAs is being treated as having
equality semantics at the RDF level, then I *think* that this is
inconsistent. I'll confess that I don't understand some of the
subtleties surrounding datatypes, so I'll let others confirm this for
me. Presuming that it *is* wrong, then this introduces the possibility
of inconsistent RDF, something that is currently impossible (with the
exception of XML literals, but that's another story), and something we
don't want. I'm more than happy for inconsistencies to be possible at
a higher level (e.g. OWL-DL), but not in RDF.

Even if I'm wrong and it's OK, I'd still feel uncomfortable building a
system that can do this.

Regards,
Paul Gearon
Received on Friday, 2 July 2010 12:27:37 UTC

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