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Re: Visualization of domain and range

From: Tim Finin <finin@cs.umbc.edu>
Date: Thu, 25 Jun 2009 13:28:56 -0400
Message-ID: <4A43B3D8.6000907@cs.umbc.edu>
To: public-lod@w3.org, public-semweb-ui@w3.org
Toby Inkster wrote:
> On Thu, 2009-06-25 at 11:59+0200, Bernhard Schandl wrote:
>> However many "newbies" to RDF and ontologies are confused by this,  
>> because the triple
>>    foaf:Agent foaf:holdsAccount foaf:OnlineAccount .
>> is actually not contained in the ontology.
> What needs to be communicated is that: 
>    [ a foaf:Agent ] ´╗┐foaf:holdsAccount [ a foaf:OnlineAccount ] . 
> instead. Those triples are not actually in the ontology itself, but will
> be found (or at least implied) in any instance data that makes use of
> the foaf:holdsAccount property.

The N3 statement '[a foaf:Agent] foaf:holdsAccount [a foaf:OnlineAccount]'
seems like an intuitive way, at least to this native English speaker,
to say that the domain and range of foaf:holdsAccount are foaf:Agent
and foaf:OnlineAccount, respectively.  I even like it.

But it doesn't really say this, does it?

Running the statement through CWM produces:

    <rdf:Description>
        <rdf:type rdf:resource="http://xmlns.com/foaf/0.1/Agent"/>
        <holdsAccount rdf:parseType="Resource">
            <rdf:type rdf:resource="http://xmlns.com/foaf/0.1/OnlineAccount"/>
        </holdsAccount>
    </rdf:Description>

Maybe I am missing some of the nuances of N3 and RDF, but I think this
defines two anonymous individuals, one which is a foaf:person (among
possibly other things) and another which is a foaf:OnlineAccount
(among possibly other things) and asserts that a foaf:holdsAccount
relations exist between them.

I don't think this says anything about the domain and range of
foaf:holdsAccount.  If we interpret this as OWL, I guess we can infer
that the domain and range are subsumed by owl:Thing.

Or maybe I am missing something.

Tim
Received on Thursday, 25 June 2009 17:29:44 UTC

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