- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Wed, 17 Apr 2002 17:42:35 -0500
- To: Patrick Stickler <patrick.stickler@nokia.com>
- Cc: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>, w3c-rdfcore-wg@w3.org
>On 2002-04-16 15:12, "ext Jos De_Roo" <jos.deroo.jd@belgium.agfa.com> wrote: > >> >> [...] >> >>> I'm still wondering about the necessity of 2b. It's not >>> quite as troublesome to me as e.g. inferring a datatype >>> property idiom from an inline idiom, but I'm still not >>> sure it is essential. >>> >>> Can you clarify for me what breaks if it is removed? >> >> well, it's just that >> entailing >> >> <http://example.org/dt#Jenny> <http://example.org/dt#age> _:z . >> _:z <http://www.w3.org/2001/XMLSchema#number> "35" . >> >> out of >> >> ( <http://www.agfa.com/w3c/n3/p7.nt> >> <http://www.agfa.com/w3c/n3/p7s.nt> ) >> >> seems ok to me >> but it's not that something would break of course > >Then, in the spirint of Occam and keeping the set of >closure rules to the bare minimum necessary to capture >the essential semantics, I'll leave it out. > >Is that OK with you, Pat? Hmmm, good question. 2b does seem *valid* and it doesn't follow from the others (does it?) so it did ought to be in a complete set of closure rules. Of course that shouldn't be taken to mean that one has to use it on every occasion, but it should be stated in the document somewhere. I guess I didn't spend too much time worrying about getting the closure rule set 'right' since it can't completely capture the idea of datatype entailment in any case, so it didn't seem to be so urgent as it was for RDFS, since there isn't going to be a datatype-entailment lemma. But let me think about that a bit more. Maybe there could be. Pat > >> >>> Also, if 2b is present, then 2a is unnecessary, since >>> the rdf:type of ?o can then be inferred from the >>> rdfs:domain of ?d. >> >> right, ok, will do that > >But now, in the absence of 2b, 2a is needed. What it >really boils down to is a choice between 2a or 2b, and >2a seems the more conservative. True, but its not clear that is a good thing when giving closure rules. The empty set of rules is always a good conservative choice :-) Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Wednesday, 17 April 2002 18:42:40 UTC