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

From: Nikita Ogievetsky <nogievet@cogx.com>
Date: Thu, 18 Dec 2003 09:45:16 -0800
To: "'Bernard Vatant'" <bernard.vatant@mondeca.com>, "'Www-Rdf-Logic@W3. Org'" <www-rdf-logic@w3.org>
Message-ID: <Law11-OE63LZCHusMjQ0000d55e@hotmail.com>

Hello Bernard,

! 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. 

Sorry, I was not selling anything, just tried to help. It was your question,
not mine. Knowing just an id of "BlueThing" was not sufficient enough to
understand what you mean. So I gave you a suggestion that you can modify as
you wish to fit definition of "BlueThing" that you have in mind. 

! 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".

Sure, you are the author, Bernard. Note though that "someValuesFrom" assumes
at least on value. So "InvisibleThing" is not included.
(Unless you start complaining that you meant invisible a la Magritte "The
Invisible World" 
http://www.the-artfile.com/uk/artists/magritte/invisibleworld.htm 
which is actually quite blue according to your latter definition of
"BlueThing")

! 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.

Consider a fading "BlueThing" eventually it becomes invisible. But at any
moment it is still blue. So there is nothing wrong with an ontology where 
InvisibleThing is a BlueThing.
In fact keeping definition of colors that you originally proposed
InvisibleThing is an intersection of BlueThing, RedThing and GreenThing.

The only thing that I am trying to say is that there is a sensible
interpretation.

With best regards,

--Nikita

PS:
When you reply please consider the fact that I do not know what you mean by
colored things and "*Thing"-s in general.


! 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 12:45:18 GMT

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