- From: <Patrick.Stickler@nokia.com>
- Date: Mon, 17 Dec 2001 03:20:34 +0200
- To: bwm@hplb.hpl.hp.com, melnik@db.stanford.edu, w3c-rdfcore-wg@w3.org
- Message-ID: <A03E60B17132A84F9B4BB5EEDE57957B160B44@trebe006.NOE.Nokia.com>
> And this led me to wondering about Patrick's suggestion that > a literal is > in fact a pair. The literal is not the pair, rather the pairing is an abstract construct that may be defined by various idioms -- but the pairing unambiguously infers/denotes/identifies a single mapping as defined in Sergey's draft. See the attached graphic for how I view the relation between mapping and pairing. Both uniquely identify a value, and a pairing denotes a specific mapping, but an explicit representation of a mapping would require a canonical representation of the value yet the pairing avoids this need by only pointing to the lexical form and data type, and relying on the defined semantics of data typing (as outlined in Sergey's draft) to ensure that only one unique value (and mapping) is unambiguously denoted by the pairing. > So what if ... > we extended n-triples so that literals MAY have an > associated datatype. This seems, in a way, to be a reduction of PDU to just PU (and the pronounciation does not necessarily mean the idea "stinks" ;-) > ... > > to a processor that 'understands' the xsd:integer and eg:oct > datatypes. My concern is that (a) we are employing vocabulary/semantics from XML Schema which may not be meaningful to other data typing schemes and (b) the kind of processing involved requires understanding of the data types themselves, so in what way is it within the scope of the RDF graph proper, more so than the semantics of any particular application-specific vocabulary (I am viewing a given data type and its associated semantics/characteristics as no different from an application specific ontology, and if applications wish to make use of knowledge expressed in specific data types/ontologies, then they must know what those data types/ontologies "mean"). The RDF graph simply captures the expression of that knowledge, not its interpretation, per se. Finally, even if we are able to handle some entailment issues without executing the actual mappings (or expressing them explicitly in the graph) I don't see how we can't handle entailment relating to the N:1 mapping from lexical space to value space (i.e. is "010" the same value as "10") without either normalizing the lexical space to a canonical lexical space or to a canonical application value space; and determination of such entailment then seems outside the scope of RDF if RDF is to remain a fully generic and application independent formalism. Eh? Cheers, Patrick -- Patrick Stickler Phone: +358 50 483 9453 Senior Research Scientist Fax: +358 7180 35409 Nokia Research Center Email: patrick.stickler@nokia.com
Attachments
- application/octet-stream attachment: data-types.png
Received on Sunday, 16 December 2001 20:20:44 UTC