abstract class

  I hope this is the place :)

  Regards,
           Marc

--- "Ralph R. Swick" <swick@w3.org> wrote:
> Date: Wed, 22 Jan 2003 14:13:18 -0500
> To: marc@jfcarrion.com
> From: "Ralph R. Swick" <swick@w3.org>
> Subject: Re: [Moderator Action] abstract class
> 
> Marc, your message (attached) was set aside for
> manual attention because the RDF Core WG mailing
> list only accepts posts from list subscribers.
> 
> I suggest you repost your comment to the public
> comments mailing list mailto:www-rdf-comments@w3.org
> as cited in the Status section of the
> RDF Schema Working Draft
> http://www.w3.org/TR/rdf-schema/
> 
> -Ralph Swick
>  W3C/MIT
> 
> At 09:17 AM 1/22/2003 -0500, Marc Carrion wrote:
> 
> 
> >  After some time ago the w3c decided to change the
> >semantics of multiple 'rdfs:range' and
> 'rdfs:domain',
> >lots of people with different ideas have discussed
> its
> >merits extensively. And although the new semantics
> >seems to work better, it has lost some of its
> >descriptive power, namely:
> >  
> >
> >    To express that the 'rdfs:domain' of a property
> is
> >A or B, we should create the class C and define A
> and
> >B as 'rdfs:subClassOf' of C; since class C remains
> >instantiable, we would like to define C as
> abstract.
> >    At first we thought we could achieve it by
> taking
> >advantage of the difference between 'Resource' and
> >'Class'; the 'rdfs:range' of the property
> 'rdf:type'
> >is 'rdfs:Class', so C could be defined as  
> ><rdf:Resource rdf:ID="C"/>. Everything would be OK
> but
> >for the fact that
> >    the 'rdfs:range' of the property
> 'rdfs:subClassOf'
> >is 'rdfs:Class' as well, hence A and B cannot be
> >subclasses of C. We considered then changing it to
> >'Resource', but then any resource of any type in
> our
> >instance would be valid as range of the property
> >'rdfs:subClassOf'.
> >    That's why we would like to propose adding a
> >'Resource' in the RDFS called 'rdfs:AbstractClass',
> >whose 'rdf:type' would be 'rdfs:Class'; 
> 'rdfs:Class'
> >would be then its 'rdfs:subClassOf', and the
> >'rdfs:range' and 'rdfs:domain' of the property
> >'rdfs:subclassof' would be this new
> >'rdfs:AbstractClass'.
> >    
> >    Regards,
> >            Marc
> >    
> >    PS: Just a thought. 'rdfs:seeAlso'
> 'rdfs:domain'
> >is 'rdf:Resource', the last resource defined in the
> >new schema
> >       <rdf:Description
> >rdf:about="http://www.w3.org/2000/01/rdf-schema#">
> >          <rdfs:seeAlso
>
>rdf:resource=http://www.w3.org/2000/01/rdf-schema-more#"/>
> >       </rdf:Description>
> >         http://www.w3.org/2000/01/rdf-schema# is
> not
> >a 'rdf:Resource', so, it can not be the domain, and
> >the same applies for
> >http://www.w3.org/2000/01/rdf-schema-more# (it
> cannot
> >be the range)
> >
> >=====
> 


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|marc_carrion@yahoo.es|
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Received on Thursday, 23 January 2003 10:29:03 UTC