RDFTM: RDF reification

[Regarding the issue of whether reification has the same
semantics in Topic Maps and RDF]

* Lars Marius Garshol
|
| I finally got round to sending that email, and this has now  
| been cleared up...
|
| If you read
| 
|    http://lists.w3.org/Archives/Public/semantic-web/2006Mar/0161.html
| 
| first, and then
| 
|    http://lists.w3.org/Archives/Public/semantic-web/2006Mar/0168.html
| 
| I think you should know what you need to.

So it is as I suspected. Really interesting thread with some
interesting implications, by the way. Nice that we "brightened
an otherwise dull evening" for Brian, as well!

| What remains is to figure out how to express TM reification if we  
| can't just use normal RDF reification.

I've been thinking about that. How about if we do EXACTLY as
currently proposed, EXCEPT that we use a class in the RDFTM
vocabulary instead of rdf:Statement?

In other words, instead of

  {puccini, bio:dateOfBirth, [[1858-12-22]]} 
    ~puccini-birthdate

translating to:

  _puccini-birthdate
    rdf:type       rdf:Statement ;
    rdf:subject   _puccini ;
    rdf:predicate  bio:dateOfBirth ;
    rdf:object    "1858-12-22" .

as currently proposed in the Section 3.8 of the Guidelines (http://www.ontopia.net/work/guidelines.html#Reification), it
translates to

  _puccini-birthdate
    rdf:type       rdftm:Relationship ;
    rdf:subject   _puccini ;
    rdf:predicate  bio:dateOfBirth ;
    rdf:object    "1858-12-22" .

The only difference being in the value of the rdf:type property.

Steve

--
Steve Pepper <pepper@ontopia.net>
Chief Strategy Officer, Ontopia
Convenor, ISO/IEC JTC 1/SC 34/WG 3
Coordinator, W3C RDF/TM Task Force
Editor, XTM (XML Topic Maps 1.0)