- From: Dave Reynolds <der@hplb.hpl.hp.com>
- Date: Mon, 10 Nov 2003 13:24:57 +0000
- To: pat hayes <phayes@ihmc.us>
- Cc: w3c-rdfcore-wg@w3.org, Jeremy Carroll <jjc@hplb.hpl.hp.com>, "Brian McBride (E-mail)" <bwm@hplb.hpl.hp.com>
pat hayes wrote:
>> In a message on 25th July [1] I noted that the tests:
>> rdfms-seq-representation/Manifest.rdf#test002
>> rdfms-seq-representation/Manifest.rdf#test004
>> appeared to be incorrect.
>
>
> No, they are correct.
The RDFCore message thread [2] responding to my previous reporting of this
seemed to indicate otherwise, I guess I misunderstood or something has changed.
> The stuff mentioned in the conclusion doesnt have
> to be mentioned in the assumption. However, it is fine for a FORWARD
> rule-based reasoner not to generate all valid conclusions from an empty
> graph, just as it would make sense not to generate everything from a
> contradiction. But think of a query-responding engine that is given the
> conclusion as a query: it could just say YES without even bothering to
> check into its KB.
We're not using a (purely) forward rule-based reasoner, we are running the
tests via a query interface, and would have no problem implementing it, if
that is the correct thing to do.
My reading of the LC2 working drafts (not the editor's draft) is that a
query to an empty model of the form:
* rdf:type rdfs:ContainerMembershipProperty
should return empty, due to the restriction of the rdfs axioms to the
vocabulary {V U crdfV U rdfsV}. Is that right (again in the LC docs not the
editor's draft)?
I guess this would be framed as a negative entailment test of the form:
"does the empty graph entail the graph:
_:a rdf:type rdfs:ContainerMembershipProperty ."
If this understanding is right then that is why I felt the vocabulary in
the conclusion does have to be mentioned in the assumptions. It would be
rather inconvenient if a query of this form returned empty but a query for
a specific rdf:_1 property returns a match.
I guess all this is now moot. I see from [3] that the semantics document
has changed to drop the crdfV restriction so the above wildcard query
should return an infinite set of matches. Is that correct?
This seems like quite a big post-LC2 change.
Dave
[2] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Jul/0324.html
[3] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Nov/0041.html
Received on Monday, 10 November 2003 08:25:11 UTC