- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Wed, 6 Feb 2002 17:25:21 -0600
- To: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Cc: w3c-rdfcore-wg@w3.org
>At 12:25 PM 2/6/02 -0600, Pat Hayes wrote: >>>I see two ways of how the semantics of reification could be attacked: >>> >>>1. Explain the semantics using bNode + 4-triple constructs. Applications >>>are free to use a compact representation. If statements are used as >>>first-class objects, they can be treated just as some kind of bNodes. >>>The API-level identity of such bNodes is functionally determined by >>>their (s,p,o)-description. Alternatively, the applications can generate >>>exactly one such bNode for each (s,p,o) etc. Same trick could be applied >>>for dealing with functionally determined bNodes in the model theory. >> >>No trick is needed. The ordinary MT already would treat the >>4-triples in this way already; reification is semantically >>transparent, on this view. Which is another way of saying that we >>are trashing it. After all, there's no way to stop anyone writing >>those 4-triples if they want to, right? Trashing it doesn't make it >>illegal, it just says that we aren't saying anything particular >>about what it means: its not a language feature, its just a way you >>might want to write some RDF. Go ahead if y'all feel like it. > >I want to pick up on two points here: > >(1) there is provision (in RDFM&S) for a reified statement to be >identified (e.g. by rdf:ID='xxx' on the corresponding property >element), so simply saying reified statements are treated as bNodes >seems to miss something. Ah, that is exactly what I wanted to focus on. WHAT DOES THAT MEAN ?? To 'identify' a reified statement, that is. Is the identifying ID a URI? If so, then why doesnt the 4-triple use that URI instead of a bnode? If not, what can 'identify' possibly mean in RDF? >(2) accepting almost all of the above that the reification >properties are mostly like any other RDF properties, we need to >express a view on this entailment: > > <ex:subj> <ex:prop> <ex:obj> . >entails > _:r <rdf:type> <rdf:Statement> . > _:r <rdf:subject> <ex:subj> . > _:r <rdf:predicate> <ex:prop> . > _:r <rdf:object> <ex:obj> . >? > >What you say above suggests no such entailment. Right. Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Wednesday, 6 February 2002 18:24:43 UTC