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Suggested OWL Full semantic changes

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Thu, 06 Feb 2003 19:35:13 +0000
Message-ID: <3E42B8F1.1010907@hpl.hp.com>
To: www-webont-wg@w3.org

Pat,

The changes I am suggesting are detailed in the last para of:

http://lists.w3.org/Archives/Public/www-archive/2003Jan/att-0107/01-t#semantics


i.e.
[[
RDFS compatible semantics are clarified to say that:

+ owl:TransitiveProperty, owl:SymmetricProperty, 
owl:InverseFunctionalProperty are all sub classes of owl:ObjectProperty 
(Also for the DL semantics)
+ In OWL full it is clarified that owl:ObjectProperty is the same class as 
rdf:Property.


]]

The motivation is syntactic.
Currently to declare that t is a transitive property you must say in OWL 
Lite, OWL DL that:

<owl:TransitiveProperty rdf:about="#t"/>
<owl:ObjectProperty rdf:about="#t"/>

i.e. you must declare that <#t> refers to an object property as well as a 
transitive one.

I would prefer if the second part could be omitted, since I believe that 
will more intelligible to users.

Whereas in OWL DL *only* object properties can be transitive properties, 
there are example transitive datatype properties in OWL Full (e.g. the 
empty one, or one which just relates non-literals to literals).

Hmmm, this is a bit tricky ...

In OWL Full:

<owl:DatatypeProperty rdf:about="#p">
    <rdfs:domain>
       <owl:Class>
           <owl:complementOf rdf:resource="&rdfs;Literal"/>
       </owl:Class>
    </rdfs:domain>
    <rdfs:range rdf:resource="&rdfs;Literal"/>
</owl:DatatypeProperty>

OWL-full-entails

<owl:TransitiveProperty rdf:about="#p"/>

Because there are no cases of x p y, and y p z.

The above is not an OWL DL entailment, because of the type mismatch (p is a 
datatype property in the first, and an object property in the second).

Also in OWL Full, p is an ObjectProperty but that is uninteresting (in OWL 
Full).

I *think* the changes work ....


Jeremy
Received on Thursday, 6 February 2003 14:35:21 GMT

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