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Re: {Disarmed} Re: blank nodes (once again)

From: Dieter Fensel <dieter.fensel@sti2.at>
Date: Thu, 24 Mar 2011 00:44:44 +0100
To: Enrico Franconi <franconi@inf.unibz.it>,Pat Hayes <phayes@ihmc.us>
Cc: Hugh Glaser <hg@ecs.soton.ac.uk>, Mark Wallace <mwallace@modusoperandi.com>, Alan Ruttenberg <alanruttenberg@gmail.com>, Reto Bachmann-Gmuer <reto.bachmann@trialox.org>, Ivan Shmakov <oneingray@gmail.com>,Ivan Shmakov <ivan@main.uusia.org>, "<semantic-web@w3.org>" <semantic-web@w3.org>
Message-ID: <E1Q2Xk2-0005ez-8v@lisa.w3.org>
Dear all,

I am not sure it is useful to add another comment and I also
only partially understand the contents of the flow of emails
on this issue. However, I will try it and risking to look like a fool.

1) bnodes are a trick to avoid thinking about useful names
in situations you do not really care about them
and used f.e. in implementing lists in RDF. Obviously
they were not really needed but make life easier.

2) Logicans entered the place and started to interpret them as
existential quantified variables. This is not wrong (since they
are statements about something that exists and has a certain
property), however, it is a somehow heavy way to interpret a
simple syntactical short-cut.

I do not think that RDF wants to forbid to interpret them as names,
only one does not care about the specific one. Maybe a straight-forward
way is to think about them as unique constants, i.e., use the idea
of skolemization. I think this is also in line with a proposal of Pat,
a down-sized version of the Jos & Enrico paper, and in sync with
[1].

Alternatively one may simply recommend to not using them (or to
read these thousand emails before using them).

Obviously, I may have missed the point, I may violate the charter, and I
should read 1000 emails more carefully.  Btw, I do not think that the
discussion is not interesting but obviously indicates a problem.

[1] G. Yang and M. Kifer: Reasoning about Anonymous Resources
and Meta Statements on the Semantic Web, J. Data Semantics, 2003: 69~97.



At 21:33 20.03.2011, Enrico Franconi wrote:

>On 18 Mar 2011, at 22:14, Pat Hayes wrote:
>
> > As a fallback, I am thinking of writing up a spec-like document 
> defining 'ground RDF', to show how much simpler everything is when 
> you don't have them. It would cover RDF, RDFS, OWL and SPARQL. What 
> do you think?
>
>In [1] we have formally explored this case.
>--e.
>
>[1] Jos de Bruijn, Enrico Franconi, Sergio Tessaris (2005). Logical 
>Reconstruction of normative RDF. Proc. of the Workshosp on OWL 
>Experiences and Directions (OWLED 2005), Galway, Ireland, November 
>2005. <http://www.inf.unibz.it/~franconi/papers/owled-05.pdf>

-- 
Dieter Fensel
Director STI Innsbruck, University of Innsbruck, Austria
http://www.sti-innsbruck.at/
phone: +43-512-507-6488/5, fax: +43-512-507-9872
Received on Wednesday, 23 March 2011 23:45:32 UTC

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