- From: Jan Grant <Jan.Grant@bristol.ac.uk>
- Date: Mon, 25 Nov 2002 15:13:46 +0000 (GMT)
- To: Graham Klyne <GK@NineByNine.org>
- cc: RDFCore Working Group <w3c-rdfcore-wg@w3.org>
On Mon, 25 Nov 2002, Graham Klyne wrote: > [Catching up...] > > I find this a little confusing: > > At 02:49 PM 11/20/02 +0000, Jan Grant wrote: > >A "negative entailment test" passes if: > > > > - P has no valid interpretations (contains a semantic error) OR > > - P is ok but does not entail C. > > In that if P has no valid interpretations I'd expect the entailment to pass > for any consequence. > > Would it not be clearer to split this into two kinds of test: > > (a) a semantic invalidity test, in which we can assert that some expression > has no valid interpretations, and > > (b) a negative entailment test: P has valid interpretations and does not > entail C. > > Or, maybe it's too late to go here? It is probably worthwhile creating such a test type; however, due to the way the MT handles DT interpretations of illegal literals, we don't need this at the moment. > Looking ahead, I see: > >D2 has semantic errors (encoded by -ve ent test, D2 -/-> E) > > This seems unexpected on two counts (E is always true, surely?). > > I note your desire to avoid a notional always-false document F - I think I > would prefer that approach rather than the modified notion of entailment > you use (but don't feel strongly enough to argue about it). I guess your > concern is that there is no way within the stated semantic constraints for > RDF to construct a document that is false under every possible interpretation? That's the problem I had, yes. -- jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/ Tel +44(0)117 9287088 Fax +44 (0)117 9287112 http://ioctl.org/jan/ Hang on, wasn't he holding a wooden parrot? No! It was a porcelain owl.
Received on Monday, 25 November 2002 10:14:03 UTC