W3C home > Mailing lists > Public > www-webont-wg@w3.org > February 2002

RE: UPDATE: why RDF syntax is not suitable for OWL

From: Smith, Michael K <michael.smith@eds.com>
Date: Fri, 15 Feb 2002 19:03:34 -0600
Message-ID: <B8E84F4D9F65D411803500508BE322140BE39653@USPLM207>
To: Pat Hayes <phayes@ai.uwf.edu>, "Smith, Michael K" <michael.smith@eds.com>
Cc: webont <www-webont-wg@w3.org>
Thanks, Pat.  That is what I was looking for. At least I understand better
what's being said. Though it still doesn't quite compute.

The N-Triples doc and the description of graphs in the MT are certainly
simple.  But from the previous version of the RDF Model and Syntax
Specification I had thought there were restrictions on the permitted
triples.  For example, that a predicate must be a Property. 

Not that this example causes a problem for the model theory.  
If foo is a class and not a property, I(<foo,foo,1>) is false.

Maybe I just need to wait for these docs to be finished.  If I read the
referenced decision below it does not specify the single place where the
syntax of RDF will be defined.  The RDF/XML is incomplete in its ability to
express RDF.  The editor of the RDF Syntax WD will include in that document
a clear statement of the RDF graph structures that RDF/XML is unable to
represent.  Perhaps as a part of that effort, the RDF Syntax WD will provide
a complete syntax for RDF triples.

- Mike

Michael K. Smith
EDS Austin Innovation Lab
98 San Jacinto, Suite 500
Austin, TX 78701
Work: 512 404-6683

-----Original Message-----
From: Pat Hayes [mailto:phayes@ai.uwf.edu]
Sent: Friday, February 15, 2002 2:08 PM
To: Smith, Michael K
Cc: webont
Subject: RE: UPDATE: why RDF syntax is not suitable for OWL

>  > I don't think the real issue has anything much
>>  to do with triples; and since so many people like triples, then why
>>  not let 'em use 'em, I would suggest.
>>  Pat Hayes
>I think it is a mistake to think 'so many people like triples'.  Maybe
>within the RDF community.  But I presume one of our goals is to create a
>standard that is adopted by a much wider community.  I would assert that
>wider community is  using XML syntax.  They are writing and using tools
>process XML.

Many are, but not all.  Every community feels that its particular 
notation is the endpoint of human evolution, of course.

>I will ask this question again: Where does the RDF standard say that its
>syntax is defined by triples?  Where is the formal triple syntax for RDF?
>All I have seen is an XML syntax.  What documents have I not read?

Go to the RDF WG website and read the current versions of the 
documents there, especially the MT and the N-triples spec.  The WG 
some time ago decided that the graph syntax (as expressed in 
Ntriples) was primary, cf. 


Resolution: On 16th November 2001, the RDFCore WG resolved:

*  The WG agrees that:
-  the graph model which is the basis for the model theory
-  the n-Triples representation of an RDF graph
-  the diagrams of graphs used in documents such as the RDF Model and 
Syntax document

are currently all equivalent

*  The WG resolves to maintain that equivalence (this is a statement 
of intent rather than a certified fact)
*  The WG notes that the RDF/XML syntax as currently defined is 
unable to represent an arbritary RDF graph. In particular, the 
RDF/XML syntax cannot fully represent a bNode which is the object of 
more than one statement.
*  The WG believes that extending the RDF/XML syntax so that it can 
represent all RDF graphs is beyond the scope of its current charter 
and resolves to postpone consideration of this issue.
*  The WG actions the editor of the RDF Syntax WD to include in that 
document a clear statement of the RDF graph structures that RDF/XML 
is unable to represent.

Currently: closed



IHMC					(850)434 8903   home
40 South Alcaniz St.			(850)202 4416   office
Pensacola,  FL 32501			(850)202 4440   fax
Received on Friday, 15 February 2002 20:03:42 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:56:41 UTC