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RE: Comments on the new RDF Test Cases draft

From: patrick hayes <phayes@ai.uwf.edu>
Date: Wed, 22 May 2002 12:04:32 -0500
Message-Id: <p05111704b9117eafaa25@[65.217.30.61]>
To: Brian McBride <bwm@hplb.hpl.hp.com>
Cc: Massimo Marchiori <massimo@w3.org>, cmjg@engarde.ioctl.org, www-rdf-comments@w3.org
>At 09:58 22/05/2002 -0400, Massimo Marchiori wrote:
>[...]
>
>>So bare-bones, suppose an RDF parser digests one of the test cases, 
>>and produces
>>all the triples we expect to (as per the "minimal interpretation" currently
>>understood in the Test Cases), plus the following triple:
>>[rdf:type] [rdf:type] [rdf:Property] .
>>Is it compliant to RDF, or not?
>
>No.

Oh dear, I said 'yes'. Perhaps Massimo has a point after all :-)

How about the following. A compliant RDF/XML parser is required to 
produce a (representation of a) syntactically equivalent graph. A 
compliant RDF inference engine is required to only make rdf-valid 
inferences. The thing that Massimo describes here is a combination of 
a compliant parser and a compliant inference engine, which is indeed 
(in some grand sense) RDF-compliant, but it's not a compliant RDF 
*parser*.

Does that make sense?

>>The set of triples that have been produced are virtually indistinguishable
>>according to the Model Theory (which is the *meaning* of a graph, 
>>independently
>>of its syntax).
>>So, if we limit ourselves to the current Test Cases interpretation, we are
>>relying on the syntactical structure rather than on the semantical one,
>>which is something I find very unelegant, and to some extent even 
>>logically broken.
>>Said this, yes, this is opinionable and no one (included me) will scream loud
>>if the "syntactical equivalence" is used rather than the semantical one.
>>However, I do think it's more elegant to go the semantic way, and 
>>can't really
>>see many advantages to go for the syntactic way.
>
>We are close to last call now, and have picked our course.  The 
>parser test cases define the transformation from RDF/XML to an 
>equivalent graph described in n-triples, where equivalence is a 
>syntactic equivalence.  That is unlikely to change unless we see 
>some specific problems with this approach.

I see no problems with it, since we have a robust notion of 
semantical equivalence which can be added to the syntactic 
equivalence if anyone wishes to do so.

Pat
Received on Wednesday, 22 May 2002 13:04:06 GMT

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