- From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Date: Mon, 29 Apr 2002 16:21:16 +0100
- To: jos.deroo.jd@belgium.agfa.com
- Cc: bwm@hplb.hpl.hp.com, patrick.stickler@nokia.com, w3c-rdfcore-wg@w3.org
Jos, I think you're right that it's a misunderstabnding... I was responding to "We build a rule mechanism", which I understood to be a means to define rules *in RDF* (similar to log:implies in N3), and which I think would be a unacceptably substantial change to RDF at this stage. If this means simply that we define some extra closure rules, then I withdraw that particular objection. Thinking aloud... would a new closure rule work? To get from: jenny age "10" . age rdfd:datatype xsd:integer . to: jenny age _:x . _:x xsd:integer "10" . We'd need a closure rule something like: { ?s ?p ?l . ?p rdfd:datatype ?d . ?l rdf:type rdfs:Literal . ) log:implies { ?s ?p _:newx . _:newx ?d ?l . } which isn't quite what the datatyping proposal currently says, because the rule fires whenever the object of ?p is something denoted by a literal, not simply when an actual literal is used. Is this the sort of thing you had in mind? Hmmm... I just found your earlier posting: [[ yes, that would be something like { :rule3a . ?p rdfd:dcrange ?d . ?p rdfd:valueProp ?q . ?s ?p ?o } log:implies { ?s ?q [ :f ( ?p ?d ?q ?s ?o ) ] } . { :rule3b . ?p rdfd:dcrange ?d . ?p rdfd:valueProp ?q . ?s ?p ?o } log:implies { [ :f ( ?p ?d ?q ?s ?o ) ] ?d ?o } . ]] Is that valid N3? What does { :rule3a . } generate? ... cwm likes it, so I suppose it's OK; doesn't generate any triples, so I suppose it's a device for labelling? Hey, even my own N3 parser thinks it's OK. I guess the [ :f ( ?p ?d ?q ?s ?o ) ] is some kind of analog of a Skolem function? I guess you might need that for proof finding, but for deductive closure ... aha, I see -- I called mine "_:newx"! And rdfd:valueProp relates the property-with-literal-range to a corresponding property-with-value-range? Taking all that on board, I guess we're talking about pretty much the same idea here. #g -- At 02:55 PM 4/29/02 +0200, jos.deroo.jd@belgium.agfa.com wrote: >[...] > > >>The Rule Fix > >>============ > >> > >>We build a rule mechanism, as in the know fix, into RDF. > > > >I think adding rules to RDF is a substantial change and out of > >scope. Especially this late in the WG cycle. > >Graham, this must be a misunderstanding >We have already 10 RDFS-entailment and RDFS closures rules in >http://www.coginst.uwf.edu/~phayes/w3-rdf-mt-draft-42402.html >and at least 3 draft ones for the RDFD-MT >that fix here is just maybe 2 extra proposed ones for the RDFD-MT > >-- >Jos ------------------- Graham Klyne <GK@NineByNine.org>
Received on Monday, 29 April 2002 11:42:04 UTC