- From: pat hayes <phayes@ai.uwf.edu>
- Date: Mon, 3 Feb 2003 16:50:49 -0600
- To: w3c-rdfcore-wg@w3.org
- Message-Id: <p05111b25ba64a0a1d19a@[10.0.100.86]>
Some XML Schema primitive datatypes are impossible to use as RDF datatypes. Therefore XSD intepretations are ill-defined. The problematic datatypes include: duration - because equality in its value space is not well defined QName - because there is no fixed lexical-to-value mapping ENTITY - because there is no fixed value space NOTATION - because there is no fixed lexical space ---- I don't consider these to be fatal problems which make it 'impossible' to use these datatypes. What is true however is that these are examples of *underdetermined* datatypes, ie datatypes about which the available information is incomplete in some way. For example, the set of durations is underdetermined; what this means is that *any* set which conforms to the XSD spec will suffice as a value space of xsd:duration, and there may be more than one such set. There may therefore be more XSD interpretations than the XML authors intended. As usual in such situations, the effect on inference is that some inferences simply cannot be made, eg it is simply unknown whether or not one xsd:duration literal can be substituted for another, so to this extent the corresponding inference rule does not apply. The text makes it clear that these rules apply only in cases where certain kinds of information are provided by the datatype information source. In sum, I don't think there is any need to do anything about this issue, except possibly to add some explanatory prose to clarify the point. Pat -- --------------------------------------------------------------------- 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@ai.uwf.edu http://www.coginst.uwf.edu/~phayes s.pam@ai.uwf.edu for spam
Received on Monday, 3 February 2003 17:49:08 UTC