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Re: Difference between cardinality=1 and FunctionalProperty?

From: Yuzhong Qu <yzqu@seu.edu.cn>
Date: Thu, 27 Mar 2003 13:08:45 +0800
Message-ID: <002b01c2f41e$f2240bc0$0f0f77ca@xobjects>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: <www-rdf-logic@w3.org>

> Both versions have the same domain for serial, so there is no difference
> here.

I agree the two versions are equal to each other in some context, shuch as "here". 

But the meaning depends  on the context. Please consider the situation the different version is imported into aother ontology, respectively.  

Thanks!

Yuzhong Qu

> I agree that serial needs to be a DatatypeProperty.
> 
> peter
> 
> 
> From: "Yuzhong Qu" <yzqu@seu.edu.cn>
> Subject: Re: Difference between cardinality=1 and FunctionalProperty?
> Date: Wed, 26 Mar 2003 23:04:41 +0800
> 
> > 
> > I think they are different. 
> > In the second one, the property "serial" can be applied to the objects
> > other than the gun.
> > 
> > One more suggestion: The property "serial" should be a DatatypeProperty.
> > 
> > Yuzhong Qu
> > 
> > > 
> > > Thanks Peter.  So you are saying that if I defined the Gun class like
> > this:
> > > 
> > >      <owl:Class rdf:ID="Gun">
> > >           <rdfs:subClassOf>
> > >                 <owl:Restriction>
> > >                         <owl:onProperty rdf:resource="#serial"/>
> > >                         <owl:maxCardinality>1</owl:maxCardinality>
> > >                 </owl:Restriction>
> > >           </rdfs:subClassOf>
> > >      </owl:Class>
> > > 
> > > then the two forms would be equivalent?  /Roger
> > > 
> > > 
> > > "Peter F. Patel-Schneider" wrote:
> > > 
> > > > From: "Roger L. Costello" <costello@mitre.org>
> > > > Subject: Difference between cardinality=1 and FunctionalProperty?
> > > > Date: Wed, 26 Mar 2003 06:39:07 -0500
> > > >
> > > > >
> > > > > Hi Folks,
> > > > >
> > > > > Aren't the below two forms essentially stating the same thing:
> > > > >
> > > > >      <owl:Class rdf:ID="Gun">
> > > > >           <rdfs:subClassOf>
> > > > >                 <owl:Restriction>
> > > > >                         <owl:onProperty rdf:resource="#serial"/>
> > > > >                         <owl:cardinality>1</owl:cardinality>
> > > > >                 </owl:Restriction>
> > > > >           </rdfs:subClassOf>
> > > > >      </owl:Class>
> > > > >
> > > > >      <owl:ObjectProperty rdf:ID="serial">
> > > > >            <rdfs:domain rdf:resource="#Gun"/>
> > > > >            <rdfs:range rdf:resource="&rdfs;#Literal"/>
> > > > >      </owl:ObjectProperty>
> > > > >
> > > > > VERSUS
> > > > >
> > > > >      <owl:Class rdf:ID="Gun"/>
> > > > >
> > > > >      <owl:FunctionalProperty rdf:ID="serial">
> > > > >           <rdfs:domain rdf:resource="Gun" />
> > > > >           <rdfs:range  rdf:resource="&rdfs;#Literal"/>
> > > > >      </owl:FunctionalProperty>
> > > > >
> > > > > Both forms state that an instance of Gun must have exactly one value
> > for
> > > > > the serial property; e.g.,
> > > > >
> > > > >      <Gun rdf:ID="SmithWesson">
> > > > >           <serial>ABCD</serial>
> > > > >      </Gun>
> > > > >
> > > > > Correct?  /Roger
> > > > >
> > > >
> > > > Not correct.  Functional properties are only partial functional.
> > Making
> > > > functional properties be total functional would cause extreme problems.
> > > >
> > > > However, replacing cardinality with maxCardinality above would do the
> > > > trick.
> > > >
> > > > Peter F. Patel-Schneider
> > > > Bell Labs Research
> > > > Lucent Technologies
> > > >
> > > > PS: It would be better to make the range of serial be xsd:string.
> > > 
> > > 
> > > 
> > 
> 
> 
Received on Thursday, 27 March 2003 00:07:49 GMT

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