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Re: RDF Extensibility

From: Dan Brickley <danbri@danbri.org>
Date: Tue, 6 Jul 2010 17:03:32 +0200
Message-ID: <AANLkTilAOMCeJu_ZQOeYUsrszWyQEPFGwfbtCFZEag3L@mail.gmail.com>
To: Jiří Procházka <ojirio@gmail.com>
Cc: Toby Inkster <tai@g5n.co.uk>, Michael Schneider <schneid@fzi.de>, Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>, Pat Hayes <phayes@ihmc.us>
2010/7/6 Jiří Procházka <ojirio@gmail.com>:
> On 07/06/2010 03:35 PM, Toby Inkster wrote:
>> On Tue, 6 Jul 2010 14:03:19 +0200
>> "Michael Schneider" <schneid@fzi.de> wrote:
>>> So, if
>>>     :s "lit" :o .
>>> must not have a semantic meaning, what about
>>>     "lit" rdf:type rdf:Property .
>>> ? As, according to what you say above, you are willing to allow for
>>> literals in subject position, this triple is fine for you
>>> syntactically. But what about its meaning? Would this also be
>>> officially defined to have no meaning?
>> It would have a meaning. It would just be a false statement. The
>> same as the following is a false statement:
>>       foaf:Person a rdf:Property .
> Why do you think so?
> I believe it is valid RDF and even valid under RDFS semantic extension.
> Maybe OWL says something about disjointness of RDF properties and classes
> URI can be many things.

It just so happens as a fact in the world, that the thing called
foaf:Person isn't a property. It's a class.

Some might argue that there are no things that are simultaneously RDF
classes and properties, but that doesn't matter for the FOAF case. The
RSS1 vocabulary btw tried to define something that was both,
rss1:image I think; but this was a backwards-compatibility hack.


Received on Tuesday, 6 July 2010 15:04:18 UTC

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