- From: Jan Grant <Jan.Grant@bristol.ac.uk>
- Date: Tue, 25 Jun 2002 15:12:25 +0100 (BST)
- To: patrick hayes <phayes@ai.uwf.edu>
- cc: w3c-rdfcore-wg@w3.org
On Tue, 25 Jun 2002, Jan Grant wrote: > > On Mon, 24 Jun 2002, patrick hayes wrote: > > > > > >Pat indicated at the F2F that entailments "accidentally" drawn would be > > >"harmless". > > > > RDF entailments, yes. > > > > >Can someone clear up this example for me? > > > > > >A: > > > <eg:foo1> <rdf:subPropertyOf> <dark:eg:foo2> . > > > <dark:eg:foo2> <rdf:subProperotyOf> <eg:foo3> . > > > > > > <eg:a> <eg:foo1> <eg:b> . > > > > > >B: > > > <eg:foo1> <rdf:subPropertyOf> <dark:eg:foo2> . > > > <dark:eg:foo2> <rdf:subProperotyOf> <eg:foo3> . > > > > > > <eg:a> <dark:eg:foo2> <eg:b> . > > > > > >C: > > > <eg:foo1> <rdf:subPropertyOf> <dark:eg:foo2> . > > > <dark:eg:foo2> <rdf:subProperotyOf> <eg:foo3> . > > > > > > <eg:a> <eg:foo3> <eg:b> . > > > > > > > > >Does A |= C? Does A |= B? B |= C? > > > > Yes: > > A|= C (by subproperty chaining and then the subproperty closure rule) > > No: > > A |= B (dark conclusion) > > Actually, for the same reason, isn't this a "yes"? Because the non-dark > statements are a strict subset of the antecedent? OK, thinking more about this: this is a technicality. However, closure rules for URL-prefix-based darkening would all have to be rewritten to not add triples if the predicate would cause darkening. With a simple bit flag then the closure rules don't need rewriting because one can simply state, "the closure rules are applied only o non-dark triples and only produce non-dark triples". s/non-dark/asserted/g if appropriate. -- jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/ Tel +44(0)117 9287088 Fax +44 (0)117 9287112 RFC822 jan.grant@bris.ac.uk Q: What's yellow and equivalent to the axiom of choice? A: Zorn's lemon.
Received on Tuesday, 25 June 2002 10:15:31 UTC