Re: PG mode and SA mode

> On Sep 18, 2019, at 11:53 AM, Olaf Hartig <olaf.hartig@liu.se> wrote:
> 
> Dear all,
> 
> There has been some confusion about the modes I have mentioned in some of the 
> other threads (PG mode and SA mode).
…
> Given a 
> nested RDF* triple, say
> 
> t = ( (s,p,o), p2, o2 ),
...
> The difference between PG mode and SA mode can also be observed if we consider 
> how RDF* graphs may be converted into standard RDF graphs based on the RDF 
> reification vocabulary: If we assume RDF* is used in SA mode, the set 
> consisting of the following five RDF triples captures the information as 
> captured by our example RDF* triple t (where b is a fresh blank node):
> 
> (b, rdf:type, rdf:Statement)
> (b, rdf:subject, s)
> (b, rdf:predicate, p)
> (b, rdf:object, o)
> (b, p2, o2)
> 
> In contrast, if RDF* is used in PG mode, our example RDF* triple t would have 
> to be converted into the following set of RDF triples, which contains one 
> additional triple (namely, the last one in the following list):
> 
> (b, rdf:type, rdf:Statement)
> (b, rdf:subject, s)
> (b, rdf:predicate, p)
> (b, rdf:object, o)
> (b, p2, o2)
> (s, p, o)

What, in this graph, identifies the bnode b with the last triple? In fact, why is it a bnode at all? Surely in this case, the subject of the reification triples should be an IRI which identifies/names the triple? But then how does this name get attached to its referent? It seems like we need some kind of naming convention here, something like

i: (s, p, o)
(:i, p2, o2)

Pat Hayes

Received on Wednesday, 18 September 2019 22:32:49 UTC