- From: Brian McBride <bwm@hplb.hpl.hp.com>
- Date: Wed, 20 Nov 2002 16:04:58 +0000
- To: Jan Grant <Jan.Grant@bristol.ac.uk>, pat hayes <phayes@ai.uwf.edu>, Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Cc: RDFCore Working Group <w3c-rdfcore-wg@w3.org>
At 14:49 20/11/2002 +0000, Jan Grant wrote: [...] > > > > We know that: > > > > <a> <b> "foo"@@en#<datatype> . > > <c> <d> "foo"@@fr#<datatype> . > > > > entails > > > > <a> <b> _:l . > > <c> <d> _:l . > > > > for all datatypes except rdf:XMLLiteral. > >It does? Doh. I think so, but don't take my word for it. Jeremy? >I still think that's broken; but I'll fix the test case. >Basically these cases outline the various issues - I'll correct them as >appropriate. Nah - see below - you got it right unless we know that datatype is not rdf:XMLLiteral. We know its not called that, but unless we make a unique name assumption, we don't know that its not another name for the same thing. [...] >NO. This is related to what Pat was complaining about. Basically, a >"Positive entailment test" with premise document P and consequent >document C passes if: > > - P has an interpretation (ie, contains no semantic errors > wrt the constraints imposed by the interpretation rules used > for the test case) AND > - P entails C. > >A "negative entailment test" passes if: > > - P has no valid interpretations (contains a semantic error) OR > - P is ok but does not entail C. OK, so because its a neg entailment of the empty graph, then by this rule, there can be no valid interpretations. I thought the model theory had bad datatype lex forms denoting something though, in which case there is an interpretation. Right, from 3.4 of the MT: [[For any typed literal "sss"^^ddd in G, if I(ddd) is in D and 'sss' is not a valid lexical form for I(ddd) then IL("sss"^^ddd) is not in LV]] and [[(this) condition requires than an 'ill-formed' typed literal, i.e. one where the literal string is not in the lexical space of the datatype, not denote any literal value. Intuitively, such a name does not denote any value, but in order to avoid the semantic complexities which arise from empty names, we requires such a typed literal to denote an 'arbitrary' value.]] Thus there are interpretations of the graph http://www.w3.org/2000/10/rdf-tests/rdfcore/datatypes/test002.nt and the test does not work [...] >I'm happy to revise this if you think it's necessary. Lets get confirmation first Brian
Received on Wednesday, 20 November 2002 11:03:33 UTC