RE: abstract model

> > 6.  There is a mapping called Reification which a maps
> >     each member s of Statements onto a unique member r
> >     of Resources.  r is known as the reficiation of s.
> >     Here unique means given s1 and s2 members of
> >     Statements, Reification(s1) = Reification(s2) iff
> >     s1 = s2. 
> I don't read the RDF spec to imply this. Instead something like:
> 	there is a relationship Reifies over {(r,s)} where
> 	r Reifies s (wrt a model m)
> 		iff
> 	m contains the statements
> 		r -[rdf:subject]-> (subject(s))
> 		r -[rdf:predicate]-> ...etc
> in other words, "a reification" instead of "the reification" is the
> right way to look at this.

You can certainly look at it as you suggest.  Lets say I do that
and I have a model which contains only the reification of some
statement s by your definition.  I now delete - lets say the
statement with rdf:subject property.  It is arguable that the
resource which is the subject of the other statements is still
the same resource and still denotes the same thing it always did.

The reason I chose to represent it the way I did, was to 
move the definition of what properties a reified statement must
have from the abstract model to the definition of the transform
between a serialization and an abstract model.  That means that
a parser can essentially choose what statements to add when it
reifies, and in practise I think that is a good thing.  Many
times one just not want all those extra subject, property
statements included.


Received on Tuesday, 12 September 2000 08:10:47 UTC