Re: Terminology: How to call "IRI or blank node"?

On 12/19/2014 11:36 PM, Holger Knublauch wrote:
>
> On 12/20/14, 4:33 PM, Eric Prud'hommeaux wrote:
>>
>> > We need a URI for that, so that we can say that "every value of a given
>> property must be a resource". Basically a way to say "anything that can
>> appear as a subject in a triple (and therefore can have its own properties).
>> We have always used rdfs:Resource for that and it worked well in practice -
>> and rdfs:Literal to say "every datatype". rdfs:NonLiteral does not exist.
>> OWL had owl:ObjectProperty and owl:DatatypeProperty, and if you left their
>> range empty then they had that default interpretation. How was this ever
>> supposed to work in RDF Schema?
>>
>> RDFS never needed to address this distinction (arguably because it's not s
>> schema language). It is certainly better to mint a new term than to confuse
>> the meaning of an existing term.
>>
>
> I would be OK with a different term but this should then become the superclass
> of all other classes, so that the inheritance model is consistent. Currently
> only rdfs:Resource can play this role I think, but that unfortunately includes
> literals. And owl:Thing would suck in way too much complexity just for this
> technical detail (and existing models that use rdfs:subClassOf rdfs:Resource
> would be excluded too).
>
> Holger
>
>

It appears that you are asking for the class whose instances are all resources 
excluding literal values.  The expressive power required for this class goes 
well beyond the bounds of RDFS.

This new class cannot be the superclass of all classes.  It is not a 
superclass of the class that is the fixed meaning of rdfs:Resource, of course, 
and it is also not a superclass of class that is the fixed meaning of 
rdfs:Literal or of any of the datatype classes.  Making this class a 
superclass of all classes would break RDFS.

It would also not be the case that the meaning of all IRIs and blank nodes 
would belong to this new classes.  In RDF the meaning of an IRI or a blank 
node can be a literal value.


peter

Received on Saturday, 20 December 2014 15:12:57 UTC