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Re: SEM: Re: more on a same-syntax extension from RDF(S) to OWL

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Tue, 05 Mar 2002 12:54:02 -0500
To: jonathan@openhealth.org
Cc: jos.deroo.jd@belgium.agfa.com, www-webont-wg@w3.org
Message-Id: <20020305125402C.pfps@research.bell-labs.com>
From: "Jonathan Borden" <jonathan@openhealth.org>
Subject: SEM: Re: more on a same-syntax extension from RDF(S) to OWL
Date: Tue, 5 Mar 2002 11:31:09 -0500

> 
> > > Perhaps an MT for N3 would be useful.
> >
> > > One of the major benefitts of N3 over
> > > RDF (including N-Triples) is the simple ability to write down a set of
> > > statements _without asserting them_.
> >
> > But RDF, can, sort of, do this.  All you do is set up a bag of reified
> > statements.  Well actually there is a lot more that you need to do if you
> > want to do useful things with this abilitity, without causing problems,
> but
> > that is not a syntax issue, but instead has to do with what such things
> > mean.
> 
> From the syntactic standpoint, RDF reification is not good, because it
> greatly complicates the syntactic expression of an unasserted triple (e.g.
> one statement becomes three, hence a three fold increase in syntactic
> complexity).
> 
> From the semantic viewpoint, the connection between a statement and a
> reified statement in the RDF MT does not exist or at the very least is not
> clear to me.

Well it is much clearer than the connection between an N3 formula and
assertions, at least for me.

> I consider it _also_ a syntactic issue, because languages which have
> cumbersome syntaxes tend not to get used*
> 
> Jonathan
> 
> *the definition of cumbersome depends on the user. However, note that I do
> not consider XML cumbersome. I do consider RDF reification cumbersome. I
> assert that a language which is designed to make heavy usage of RDF
> reification will be cumbersome (short of changing the syntactic definition
> of RDF reification).

I definitely agree with you that RDF reification is cumbersome.  But that
doesn't make N3 formulae significantly better than RDF reification.  In
fact, the (only) meaning given for N3 is via an underspecified ``mapping into
the RDF data model'', so somehow N3 formulae have to be mapped into RDF.

peter
Received on Tuesday, 5 March 2002 14:41:18 GMT

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