Comments from RDFCore on S+AS from Brian McBride on 2003-05-09 (public-webont-comments@w3.org from May 2003) (original) (raw)

The RDFCore WG has me to forward the comments below on their behalf. Other comments, on behalf of RDFCore will be sent in separate messages.

Brian

owlsas-rdfcore-np-complete

RDFCore notes the a consequence of the rules for owl:equivalentClass is that distinguishing OWL DL from OWL Full has complexity NP complete and suggests WEBONT investigate whether this complexity can be reduced.

We note from the RDF semantics document

[[ Specifications of such syntactically restricted semantic extensions MUST include a specification of their syntactic conditions which are sufficient to enable software to distinguish unambiguously those RDF graphs to which the extended semantic conditions apply. ]] http://www.w3.org/TR/rdf-mt/

owlsas-rdfcore-bnodes-restrictions

RDFCore are concerned that restrictions placed on b-nodes will limit the applicability of OWL DL to an unnecessarily restricted subset of RDF instance data, for which no such restrictions apply.

For example, consider the use case in:

http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003May/0109.html

[[ If bNodes can only be used as the object of a single triple, they lose most of their value as a construct in the language. As does rdf:nodeID for that matter.

...is OK in OWL, but if we add in an rdf:nodeID on the two Person elements to express that they serialize descriptions of the same (un-named) resource, we're in trouble? Ouch. That breaks most of my uses of RDF, and a lot of deployed FOAF documents. ]]

Specifically we request, that in Owl DL and Owl lite:

a) that a b-node representing an individual may be the object of more than one triple b) that cycles of b-nodes representing individuals be allowed.

Received on Friday, 9 May 2003 13:02:55 UTC