Fwd: problems with RDF datatyping

 From PFPS:

>In trying to make the OWL semantics correspond to the RDF semantics I came
>up with the following problems in RDF datatyping:
>
>1/ A datatype is an element of IR, because the RDF MT says that datatypes are
>denoted by URI references.  However, rdf:XMLLiteral is said to be a
>datatype, but rdf:XMLLiteral is a URI reference.  Something is wrong here.
>
>2/ XSD-interpretations include in their datatypes the XML Schema datatypes
>that are problematic when removed from XML documents or have other
>problems.  XSD-interpretations also include, for example, the datatype
>named FOO, which is not defined as an XML datatype.
>
>3/ A datatype has to be more than is specified in the RDF MT.  Except for
>XSD-interpretations, which explicitly mention the URI-reference to datatype
>relationship, there is no way of tying the intended URI-reference for a
>datatype to that datatype.  For example, if I have D containing a datatype
>for integers and a datatype for strings, there is no way to require that a
>particular URI reference, say ex:int, denotes the integer datatype.
>
>
>It probably makes more sense to say that a datatype is a four-tuple,
>consisting of a URI reference, a lexical space, a value space, and a
>lexical-to-value mapping.
>
>
>Peter F. Patel-Schneider
>Bell Labs Research
>Lucent Technologies

Received on Friday, 17 January 2003 06:31:11 UTC