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

From: Bernard Vatant <bernard.vatant@mondeca.com>
Date: Thu, 18 Dec 2003 15:48:25 +0100
To: "Nikita Ogievetsky" <nogievet@cogx.com>, "'Www-Rdf-Logic@W3. Org'" <www-rdf-logic@w3.org>
Message-ID: <GOEIKOOAMJONEFCANOKCCEBHCOAA.bernard.vatant@mondeca.com>


Hello Nikita

There are so many possible definitions for a blue thing. Yours would be
good for Klein's "Monochrom Blue". Sorry, I don't buy those. I prefer the
blue a la Kandinsky.

See http://webexhibits.org/pigments/indiv/color/blues4.html

That said, I would buy your definition for blue-only things, replacing
cardinality by minCardinality to accept a wider bandwidth of blue on a
single object. And to include Kandinsky's "In the Blue", I would keep the
original definition with "someValuesFrom" instead of "allValuesFrom".

Anyway, you missed my point ... I'm not looking for any *better* definition
of BlueThing. I want to figure out what that one, as it is, means for
InvisibleThing.

Cheers

Bernard

Bernard Vatant
Senior Consultant
Knowledge Engineering
Mondeca - www.mondeca.com
bernard.vatant@mondeca.com


> -----Message d'origine-----
> De : Nikita Ogievetsky [mailto:nogievet@cogx.com]
> Envoye : jeudi 18 decembre 2003 14:55
> A : 'Bernard Vatant'; 'Www-Rdf-Logic@W3. Org'
> Objet : RE: erratum ... RE: allValuesFrom and rdfs:domain
>
>
> 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 09:48:42 GMT

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