- From: pat hayes <phayes@ihmc.us>
- Date: Tue, 2 Sep 2003 23:42:29 -0700
- To: Jan Grant <Jan.Grant@bristol.ac.uk>, Jeremy Carroll <jjc@hpl.hp.com>
- Cc: w3c-rdfcore-wg@w3.org
>On Tue, 2 Sep 2003, Jeremy Carroll wrote: > >> >> >> Summary: >> Prefer c++ >> modify the test case to say that the case is D-consistent with the >> empty graph, not that it is D-entailed by it; >> add D-inconsistent test using a different rdfs:subClassOf triple between >> xsd datatypes. >> >> >> >> >> pat hayes wrote: >> >> >> > (a) modify the test case doc by deleting the test case; >> >> Not particularly OK, well unless the semantics doc discusses >> rdfs:subClassOf in datatyping clearly. i.e. this should not be left as an > > exercise for the reader. Currently I have this text where the rule rdfD4 used to be: "In addition, if it is known that the value space of the datatype denoted by ddd is a subset of that of the datatype denoted by eee, then it would be appropriate to assert that ddd rdfs:subClassOf eee . but this needs to be asserted explicitly; it does not follow from the subset relationship alone." > > >> > (b) modify the test case to say that this only follows under the >> > strengthened extensional semantic conditions on rdfs:subClassOf >> > described in section 4.1 of the semantics document; >> >> not good >> >> > (c) modify the test case to say that the case is D-consistent with the >> > empty graph, not that it is D-entailed by it; >> >> OK >> Also add a test case showing that >> xsd:string rdfs:subClassOf xsd:integer . >> is inconsistent. >> >> > (d) modify the semantics of D-interpretations to insist that datatype >> > class subsetting *is* treated extensionally, so that the rule rdfD4 is >> > valid and the test case is OK. This can be done by adding the following >> > semantic condition on D-interpretations: >> >> Prefer (c) to this. >> (Another option is to explicitly list rdfs:subClassOf relationships between >> xsd datatypes as true by fiat). > >This last option seemed the "obvious" one to me: that a datatype >definition might well include subClassOf "axiomatic triples". Well, if these are considered part of some external-to-RDF definition of some class of datatypes, then that is fine. I have no problem with that. > >The test case document currently doesn't have explicit >"consistent/inconsistent" test cases; these have usually been encoded >using entailment or non-entailment of false graphs. Well, if y'all are happy to phrase things this way, then OK; but there is no such thing as a false graph, actually. About the best you could do to get a contradiction in RDF would be to have an XML literal clash, such as ex:a ex:p "<NotALegalXMLString"^^rdf:XMLLiteral . ex:p rdfs:range rdf:XMLLiteral . >So the new test cases would be that: > >1. >[[ > xsd:integer rdfs:subClassOf xsd:decimal . >]] DOES NOT rdfs+D(xsd:integer, xsd:decimal)-entail >[[ FALSE ]] (the "false" graph) > >2. >[[ > xsd:integer rdfs:subClassOf xsd:string . >]] rdfs+D(xsd:integer, xsd:string)-entails >[[ FALSE ]] > >... is that ok? Yes, modulo the above. Pat > > > > > >-- >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/ >It's a sad fact that the word "semantics" seems to have lost all meaning. -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
Received on Wednesday, 3 September 2003 02:43:23 UTC