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Re: a possible syntax error in equivalentProperty/premises005 ?

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Wed, 19 Nov 2003 14:00:43 +0000
Message-ID: <3FBB778B.3000005@hplb.hpl.hp.com>
To: minsu@etri.re.kr, public-webont-comments@w3.org

[[
	<owl:Restriction rdf:nodeID="d">
		<owl:onProperty rdf:resource="#p"/>
		<owl:onProperty rdf:resource="#q"/>
		<owl:hasValue rdf:resource="#v"/>
	</owl:Restriction>

According to AS&S, this looks invalid, because restrictions can have
only one
individualvaluedPropertyID or datavaluedPropertyID.

But, Jena[1] and OWL Ontology Validator[2] successfully parse the
document.
I'm confused. Any comments on this?
]]

The test states that the file is in OWL Full.
This agrees with your observation, that in OWL DL, S&AS says that this is 
not permitted.
Any RDF document is an OWL Full document.

The OWL Full semantics is given in section 5 of S&AS and we read:
http://www.w3.org/TR/owl-semantics/rdfs.html#5.2

Conditions on OWL restrictions
[[
if
<x,y>∈EXTI(SI(owl:hasValue))) ∧
<x,p>∈EXTI(SI(owl:onProperty)))
then
]]


and we see that both properties fulfil this condition.

Hence the expression is semantically equivalent to something like:

<owl:Restriction rdf:nodeID="d">
    <owl:onProperty rdf:resource="#q"/>
    <owl:hasValue rdf:resource="#v"/>
    <owl:eqivalentClass>
       <owl:Restriction>
          <owl:onProperty rdf:resource="#p"/>
          <owl:hasValue rdf:resource="#v"/>
       </owl:Restriction>
    </owl:equivalentClass>
</owl:Restriction>


The software you mention should report that the test file is in Full.

Jeremy
Received on Wednesday, 19 November 2003 09:00:58 GMT

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