RE: Summary of the QName to URI Mapping Problem

> >But is this really an interaction of the semantics of the RDF graph
> >and the semantics of the URI? I.e., aren't such mechanisms 
> really just
> >instructions to the parser?
> 
> You can look at it that way, indeed, and that might be the easiest 
> way for just this. I guess my point is really only a kind of gut 
> feeling/worry that we are going to have to be sensitive to ways in 
> which the classical syntax/semantic layerings are going to get more 
> complicated. Here's another example, from the RDF M&S (which has all 
> kinds of wierd stuff in it, by the way, that seems to be very little 
> used): section 3.4, aboutEachPrefix, which takes a URI prefix and 
> asserts something about all the things that are on the web that can 
> be retrieved by adding some extension to it. We didnt even try to 
> give this a formal meaning in the RDF model theory, but in order to 
> do so one would need to 'cross layers' rather drastically (not to 
> describe the result of 'expanding' aboutEachPrefix, thought of as a 
> preprocessing step - the current workaround - but to treat it as a 
> genuine language element and give it a coherent formal semantics.)

But could not one consider that aboutEachPrefix is by nature somehow
contrary to the opaque quality of URIs in the graph and therefore not
part of the graph layer, but rather a form of processing instruction
to be applied to graphs, like a specialized query? Similar to the
DAML 'include' instructions for fetching in other schemas. Thus, it
needs no formal meaning in the RDF model theory. 

> Well, yes, in the RDF graph of a piece of DAML. But to be fair, DAML 
> itself doesnt claim to be a graph-based language.

Fair enough, though I was mostly thinking of the actual RDF graph, 
i.e. that which would be distilled into triples. I.e., even though
'include' instructions constitute extra information for a DAML parser, 
is that information also included in the RDF graph representation 
itself? From what I understand, it is not, so such instructions are
not part of the "semantics" of the RDF graph itself, right?

Regards,

Patrick

--
Patrick Stickler                      Phone:  +358 3 356 0209
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Received on Friday, 31 August 2001 00:12:00 UTC