- From: Jonathan Borden <jonathan@openhealth.org>
- Date: Tue, 09 Sep 2003 21:03:09 -0400
- To: Bob MacGregor <macgregor@ISI.EDU>
- Cc: www-rdf-logic@w3.org
Bob MacGregor wrote:
>
> st1 rdf:type rdf:Statement.
> st1 rdf:subject s1.
> st1 rdf:predicate location.
> st1 rdf:object antwerp.
> st1 beginDate "March 2003".
> st1 endDate "March 2003".
> st1 author john.
>
> st2 rdf:type rdf:Statement.
> st2 rdf:subject s1.
> st2 rdf:predicate location.
> st2 rdf:object antwerp.
> st2 beginDate "April 2003".
> st2 endDate "April 2003".
> st2 author sue.
>
> My intent is that 'st1' and 'st2' are both reifications of the
> same statement [s1 location antwerp]. My question is, are
> st1 and st2 the same resource, or are they two distinct
> resources?
>
st1 and st2 are distinct (at the very least they have different authors
etc.). Now as written you might be inclined to assert:
st1 owl:sameAs st2 .
of course at this point you'd have multiple authors, begin dates and end
dates.
Now you might be tempted to define :beginDate as having a cardinality=1,
if you did that your would be asserting that:
"March 2003" = "April 2003"
which is a contradiction.
>
> P.S., I don't consider the above encoding to be a particularly good
> use of RDF reification, but that's not germane to my question
> in this posting.
>
A fundamental problem with RDF reification is that there is no way to
'connect' the statement e.g. "st1" with the RDF statement {s1 location
antwerp} i.e. rdf:Statment, rdf:subject etc. have no magic. This makes
RDF reification not very useful.
Jonathan
Received on Tuesday, 9 September 2003 21:11:52 UTC