- 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