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RE: erratum ... RE: allValuesFrom and rdfs:domain

From: Nikita Ogievetsky <nogievet@cogx.com>
Date: Thu, 18 Dec 2003 05:55:15 -0800
To: 'Bernard Vatant' <bernard.vatant@mondeca.com>, "'Www-Rdf-Logic@W3. Org'" <www-rdf-logic@w3.org>
Message-id: <0HQ3005IHFZU5V@mta10.srv.hcvlny.cv.net>

Hi Bernard,

My guess is that something like this should fix your class definition:

<owl:Class rdf:ID="BlueThing">
  <owl:intersectionOf rdf:parseType="Collection">
    <owl:Restriction>
      <owl:onProperty rdf:resource="#color" />
      <owl:allValuesFrom rdf:resource="#ShadeOfBlue" />
    </owl:Restriction>
    <owl:Restriction>
      <owl:onProperty rdf:resource="#color" />
      <owl:cardinality
           rdf:datatype="&xsd;nonNegativeInteger">1</owl:cardinality>    
    </owl:Restriction>
  </owl:intersectionOf>
</owl:Class>


--Nikita


! -----Original Message-----
! From: www-rdf-logic-request@w3.org [mailto:www-rdf-logic-request@w3.org]
! On Behalf Of Bernard Vatant
! Sent: Thursday, December 18, 2003 2:00 AM
! To: Bernard Vatant; Www-Rdf-Logic@W3. Org
! Subject: erratum ... RE: allValuesFrom and rdfs:domain
! 
! 
! 
! Oops ... Please read below
! 
! <owl:Class rdf:ID="InvisibleThing">
!   <owl:complementOf>
!     <owl:Class rdf:about="#VisibleThing"/>
!   </owl:complementOf>
! </owl:Class>
! 
! instead of
! 
! <owl:Class rdf:ID="InvisibleThing">
!   <owl:complementOf>
!     <owl:Class rdf:about="#VisibleObject"/>
!   </owl:complementOf>
! </owl:Class>
! 
! Thanks
! 
! Bernard Vatant
! Senior Consultant
! Knowledge Engineering
! Mondeca - www.mondeca.com
! bernard.vatant@mondeca.com
! 
! 
! > -----Message d'origine-----
! > De : www-rdf-logic-request@w3.org
! > [mailto:www-rdf-logic-request@w3.org]De la part de Bernard Vatant
! > Envoye : jeudi 18 decembre 2003 10:38
! > A : Www-Rdf-Logic@W3. Org
! > Objet : owl:allValuesFrom and rdfs:domain
! >
! >
! >
! >
! > I need some help from experts in logic ...
! >
! > I've sent a few days ago a message about "TexasThings" example
! > in OWL Guide
! > (see below), where the interpretation of allValuesFrom seems wrong to
! me.
! > Without answer so far from there, I push the question here.
! >
! > Suppose I have the following - more enlightening to me at least
! > than Texas
! > Things :))
! >
! > <owl:Class rdf:ID="BlueThing">
! >   <owl:equivalentClass>
! >     <owl:Restriction>
! >       <owl:onProperty rdf:resource="#color" />
! >       <owl:allValuesFrom rdf:resource="#ShadeOfBlue" />
! >     </owl:Restriction>
! >   </owl:equivalentClass>
! > </owl:Class>
! >
! > <owl:ObjectProperty rdf:ID="color">
! >   <rdfs:domain rdf:resource="#VisibleThing"/>
! > </owl:ObjectProperty>
! >
! > What can be asserted between the classes BlueThing and VisibleThing ?
! >
! > Of course, if some BlueThing X has a value for "#color", then X is in
! the
! > domain of "#color". But using "allValuesFrom" means that some other
! > BlueThing Y may not have any value at all for this property.
! > How can this happen? Quite naturally, if Y is not a VisibleThing
! > one might
! > not be able to specify any value for its color. One knows somehow Y is a
! > BlueThing, without being able to specify any ShadeOfBlue.
! >
! > So a BlueThing is not necessarily a VisibleThing.
! >
! > There is more tricky.
! >
! > <owl:Class rdf:ID="InvisibleThing">
! >   <owl:complementOf>
! >     <owl:Class rdf:about="#VisibleObject"/>
! >   </owl:complementOf>
! > </owl:Class>
! >
! > Does the following triple hold?
! >
! > InvisibleThing  rdfs:subClassOf  BlueThing
! >
! > Sounds weird ... but I can't find any solid argument against it.
! >
! > Bernard
! >
! > Bernard Vatant
! > Senior Consultant
! > Knowledge Engineering
! > Mondeca - www.mondeca.com
! > bernard.vatant@mondeca.com
! >
! >
! > -----Message d'origine-----
! > Envoye : lundi 15 decembre 2003 19:21
! > A : public-webont-comments@w3.org
! > Objet : TexasThings and owl:equivalentClass
! >
! > Seems to me that there is something wrong, or at least
! > misleading with the
! > example of "TexasThings"
! > http://www.w3.org/TR/owl-guide/#equivalentClass1
! >
! > <owl:Class rdf:ID="TexasThings">
! >   <owl:equivalentClass>
! >     <owl:Restriction>
! >       <owl:onProperty rdf:resource="#locatedIn" />
! >       <owl:allValuesFrom rdf:resource="#TexasRegion" />
! >     </owl:Restriction>
! >   </owl:equivalentClass>
! > </owl:Class>
! >
! > First it would certainly be better to have the singular
! > "TexasThing" rather
! > than plural "TexasThings" :)
! >
! > "TexasThings are exactly those things located in the Texas region ..."
! >
! > This is obviously wrong. There is an allValuesFrom, but not a
! > someValuesFrom here. As defined, it means : If TexasThings are located
! > somewhere, they are located in Texas region.
! >
! > An further on
! >
! > " ... The difference between using owl:equivalentClass here and using
! > rdfs:subClassOf is the difference between a necessary condition and a
! > necessary and sufficient condition. With subClassOf, things that are
! > located in Texas are not necessarily TexasThings. But, using
! > owl:equivalentClass, if something is located in Texas, then it must be
! in
! > the class of TexasThings."
! >
! > ... but not the other way round, unfortunately.
! >
! > In fact under this definition any thing located nowhere is a Texas
! Thing.
! > Thinking about it, maybe it makes sense after all. Nowhere is indeed in
! > Texas, and especially its middle ... :))
! >
! >
! >
! 
! 
Received on Thursday, 18 December 2003 08:55:47 GMT

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