W3C home > Mailing lists > Public > www-rdf-interest@w3.org > March 2001

Re: Question: Can a RDF Class and a RDF Property have the same name?

From: Gustaf Neumann <neumann@wu-wien.ac.at>
Date: Thu, 15 Mar 2001 11:24:45 +0100
To: "Balon, Corey" <cbalon@grci.com>, "'puninj@cs.rpi.edu'" <puninj@cs.rpi.edu>, www-rdf-interest@w3.org
Cc: rss-dev@egroups.com
Message-Id: <0103151124450P.05860@mohegan.wu-wien.ac.at>
On Wednesday 14 March 2001 22:41, Balon, Corey wrote:
> Hey,
> I don't believe they can.

 i believe they can, but it would not conclude that this
 is a good style.

 since the type is a property, and it is valid to define multiple triples with
 the same poperty name to a resource, this should be perfectly from this 
 perspective.  I am not aware of any kind of constraints in this regard.

 However, if it is defined like this, it is obviously not possible to
 define different properties for the "Property" and "Class" roles of the resource.


> Class and Property are both Resources. A URI is unique
> for a Resource, so two resources should have different URI's.
> I'm not sure if there is some rule against it, but I don't
> believe it is something you would ever want to do.
> When in doubt I always look at the triples.
> The rdf you gave should turn into triples that look something
> like this:
> (http://purl.org/rss/1.0/image, type, Class)
> (http://purl.org/rss/1.0/image, type, Property)
> (http://purl.org/rss/1.0/image, label, "Image")
> (http://purl.org/rss/1.0/image, label, "image")
> (http://purl.org/rss/1.0/image, comment, "An RSS image.")
> (http://purl.org/rss/1.0/image, comment, "Points to an image that is a
> member of the subject channel.")
> ...
> You see here that everything gets mashed together. The origin of each
> statement
> is not clear. Something processing these triples would not see a Class and
> a Property,
> but some weird hybrid thing.
> -Corey
> -----Original Message-----
> From: puninj@cs.rpi.edu [mailto:puninj@cs.rpi.edu]
> Sent: Wednesday, March 14, 2001 4:09 PM
> To: www-rdf-interest@w3.org
> Cc: rss-dev@egroups.com
> Subject: Question: Can a RDF Class and a RDF Property have the same
> name?
> Hi
> I was reading about RSS 1.0 and I tried to updated the RSS-1.0-RDF-Schema.
> I found that "image" is a RDF property of "channel" RDF Class and also a
> RDF Class.
> Can a RDF class have the same name (URI) of a RDF Property?.  I'm sure that
> this issue has been discussed before but I didn't find anything in this
> e-mail
> list.
> If the answer of this question is yes. That means that I can write the RSS
> Schema as:
> <rdfs:Class rdf:about="http://purl.org/rss/1.0/image"
>    rdfs:label="Image"
>    rdfs:comment="An RSS image.">
>    <rdfs:isDefinedBy rdf:resource="http://purl.org/rss/1.0/"/>
>  </rdfs:Class>
> <rdfs:Property rdf:about="http://purl.org/rss/1.0/image"
>    rdfs:label="image"
>    rdfs:comment="Points to an image that is a member of the subject
> channel.">
>    <rdfs:isDefinedBy rdf:resource="http://purl.org/rss/1.0/"/>
>    <rdfs:domain rdf:resource="http://purl.org/rss/1.0/channel"/>
>    <rdfs:range
> rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource">
> </rdfs:Property>
> Thanks for your help in this matter.
> John Punin
Received on Thursday, 15 March 2001 05:25:08 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 22:44:29 UTC