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What's the difference? rdf:about, owl:sameIndividualAs

From: Jimmy Cerra <jimbobbs@hotmail.com>
Date: Fri, 16 May 2003 23:24:42 -0400
To: <www-rdf-logic@w3.org>
Message-ID: <000001c31c23$db1efca0$1a6afea9@picard>

What's the difference between rdf:about and owl:sameIndividualAs?  They
all seem to be used to define a resource.  Take the following example:

<owl:Thing rdf:about="uri#foo" />

That serialized RDF statement says that a resource, identified by
"uri#foo", is an individual (as defined by OWL).  However, I could also
say that a blank node that is identical to the resource identified by
"uri#foo" is an individual:

<owl:Thing>
	<owl:sameIndividualAs rdf:resource="uri#foo" />
</owl:Thing>

From that statement, an agent should conclude that the resource
identified by "uri#foo" has the same properties as that blank node.
Since the blank node is an individual, then the resource identified by
"uri#foo" must have the same properties - mainly that it is an
individual.  So rdf:about and owl:sameIndividualAs can be used to
identify a resource; the former by direct statements and the latter by
inference.

Is it really necessary to have two different ways of saying the same
thing?  Perhaps so; then would it be advantageous to make the rdf:about
attribute an actual property?  For example:

<owl:Thing>
	<rdf:about>uri#foo</rdf:about>
	<rdf:about>uri#bar</rdf:about>
</owl:Thing>

or:

<owl:Thing>
	<rdf:about rdf:resource="uri#foo" />
	<rdf:about rdf:resource="uri#bar" />
</owl:Thing>

as opposed to:

<owl:Thing rdf:about="uri#foo">
	<owl:sameIndividualAs rdf:resource="uri#bar" />
</owl:Thing>

or:

<owl:Thing>
	<owl:sameIndividualAs rdf:resource="uri#foo" />
	<owl:sameIndividualAs rdf:resource="uri#bar" />
</owl:Thing>

???  

--
Jimmy Cerra

] "My mind is slipping away...
]  day by glorious day." - RAG III
Received on Friday, 16 May 2003 23:24:49 GMT

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