- From: Dan Connolly <connolly@w3.org>
- Date: 30 Jan 2002 09:41:44 -0600
- To: Brian McBride <bwm@hplb.hpl.hp.com>
- Cc: Jeremy Carroll <jjc@hplb.hpl.hp.com>, RDF core WG <w3c-rdfcore-wg@w3.org>
On Wed, 2002-01-30 at 08:54, Brian McBride wrote: > Ok Jeremy, > > As I understand what you are suggesting here, is that under TDL, the rule > could be rewritten to get the desired effect, i.e. reflecting the "literal > is a pair" directly in an extended n-triples represention: > > <mary> <haircolor> (_, "red") . > > and > > ?x <haircolor> (_, "red") => ?x <rdf:type> <redhead> . > > one can conclude: > > ?x <rdf:type> <redhead> . > > DanC - Do you buy this one. Rewrite the rule and you get what you want. I accept the reasoning above; it doesn't address my objection; it' just shows that my example wasn't very good. Sergey's example makes the point better: --8<-- _:f <rdf:type> <film> . _:f <dc:Title> "10" . <mary> <age> "10" . Given a query: (?x <dc:Title> ?y) & (?z <age> ?y) --8<-- As to the claim that query is irrelevant, I disagree; it's clearly analagous to an entailment test: premise: _:f <rdf:type> <film> . _:f <dc:Title> "10" . <mary> <age> "10" . conclusion: _:x <dc:Title> _:y. _:z <age> _:y. pass or fail? Clearly when viewed in TDL-extended-N3 as above... _:f <rdf:type> <film> . _:f <dc:Title> (_:t1, "10") . <mary> <age> (_:t2, "10") . it's not valid to conclude _:x <dc:Title> _:y. _:z <age> _:y. The TDL proponents claim this is a feature: the two occurences of "10" might indeed denote different things. I see it as a bug: I think RDF users expect "10" to match "10". This seems to put the two positions in pretty stark contrast. -- Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Wednesday, 30 January 2002 10:42:31 UTC