Re: Followup 2: The Heart of RDF Darkness

Jeff Sussna wrote:
> 
> Given the notion of reification, it would be nice to be able to simply say
> "property X defined within description Y has the timeframe 1987-1993". As
> far as I can tell, however, this is impossible, since there is no way to
> make a statement about a single member of a container (the contained in this
> case being the Bag of property statements contained by the description).

Taken from the formal grammar section of the spec:

   Within propertyElt (production [6.12]), the URI used
in
   a resource attribute identifies (after resolution) 
   the resource that is the object of the statement
(i.e., 
   the value of this property). The value of the ID 
   attribute, if specified, is the identifier for the
   resource that represents the reification of the 
   statement. 

Note the second sentence. I don't think that this
information is maintained by current parsers but it
does allow you to identify the reification of a
specific statement in a description. 

If it was supported, you could say:

<rdf:Description about="Jimmy">
  <playsFor rdf:ID="44" rdf:resource="Pirates"/>
  <playsFor rdf:ID="55" rdf:resource="Brigands"/>
</rdf:Description>

<rdf:Description about="#44">
   <startDate>2/3/78</startDate>
   <endDate>2/2/81</endDate>
</rdf:Description>

<rdf:Description about="#55">
   <startDate>2/3/81</startDate>
   <endDate>2/2/83</endDate>
</rdf:Description>

Cordially from Corvallis,

Gabe Beged-Dov

Received on Thursday, 30 December 1999 18:55:55 UTC