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owl.owl (was: OWL 2 -- Call for Implementations, new Drafts)

From: Holger Knublauch <holger@topquadrant.com>
Date: Tue, 21 Jul 2009 15:22:59 -0700
Message-Id: <B6D22E33-5332-4CF3-8582-F6A033BE4C7B@topquadrant.com>
To: public-owl-dev@w3.org
Sorry for picking up this old thread. There have been some other  
messages on the OWL comments mailing list (see [1]), and Bijan  
suggested [2] I return to this list. This is mainly a response to  
Bijan's message.

The topic is whether there should be an owl.owl file with RDF triples  
for the OWL (2) vocabularies, maintained by the OWL working group. I  
suggest doing this, and I am glad that my request is being (albeit, by  
some, reluctantly) moved forward.


Bijan Parsia wrote:
 > If you follow the link I in:
 >	http://lists.w3.org/Archives/Public/public-owl-wg/2009Jul/0030.html
 > You'll see that the idea of importing SWRL.owl is exactly what I  
argue
 > against, so it's a bit odd to appeal to it as an exemplar.

I have been reading your message [3] but don't think it contains any  
arguments apart from that importing SWRL would make ontologies become  
OWL Full. The other arguments just seem to repeat that importing SWRL  
is a bad idea because you don't think this is a good practice.  
Importing SWRL shares some of the advantages of importing the OWL  
namespace. For example, users of editing tools can see the definitions  
of the SWRL built-ins, use auto-complete, tool tip texts and any other  
infrastructure that they will expect. Whether this makes the files OWL  
Full is from my point of view completely irrelevant. If inference  
engines have problems with that, then they can happily ignore those  
triples and imports. This is easily supported by APIs such as Jena,  
because you just need to remove a sub-Graph from a UnionGraph. But  
IMHO it is cleaner to operate on well-defined terms that are backed by  
real URIs and helpful background information like rdfs:labels,  
rdfs:comments etc.


 > I'm well aware of how systems use such files (as is clear by my
 > reference to SWI Prolog), but think that that use is by and large
 > misguided and sometimes harmful. The implementation burden reduction
 > is generally quite minimal, IMHO.

In my experience the implementation burden without an OWL.owl file  
would be immense and would significantly slow down any support for OWL  
2 in our tools. So I do not share your view and claim the opposite  
(for our use cases).


 > In any case, there's no need for a
 > central "canonical" version of the file in order for you to use this
 > implementation technique. Nothing stops TopBraid from using this sort
 > of mechanism internally.

This is what I would need to do if the work group would not want to  
deliver such a file in a central place. Fortunately, I am not the only  
person with this request, and I appreciate that Michael Schneider has  
already taken very good first steps. I'd be happy to help with testing  
if this vocabulary moves along.


 > Indeed, I hope you cache your copy of owl.owl
 > instead of hitting the W3C server each time! (I would be shocked if
 > you didn't cache, but not everyone is conscientious.)

Sure, we are using the cached file embedded in the Jena API.


 > I don't find the linked data argument compelling as fundamental
 > enabling technology doesn't need to use distributed extensibility
 > mechanisms (unlike, for example, ad hoc vocabularies). This is not an
 > uncommon view, nor is it is in any way in tension with the growth of
 > the web or the semantic web.

My main point (and this is probably why I want to bring this thread  
back to life) is that there is IMHO no fundamental difference between  
the OWL vocabulary and any other ontology, such as SWRL, FOAF or SIOC.  
OWL is an RDF vocabulary for defining classes and properties. The  
instances of the OWL ontology are (mostly) classes and properties.  
FOAF is a vocabulary for describing people. Many Semantic Web tools  
such as TopBraid only require very minimal hard-coding against  
specific ontologies, and in our case this is mostly against RDF  
Schema. So the tool has some special handling of the RDFS metaclasses,  
and - with the OWL system ontology - this is sufficient for much of  
OWL support as well. The beauty of having the OWL system ontology is  
that we (and other tool developers) don't need to worry about all the  
"exotic" features such as owl:ReflexiveProperty - as long as we know  
that this is a property metaclass then the tool knows what to do with  
it. If users want OWL 2 support, they would just add those triples. If  
they prefer to stay in OWL 1, they would not.

Of course, the OWL vocabulary is fundamentally different from the  
point of view of OWL tools such as tableau inference engines. But as  
OWL RL nicely illustrates, even these things can often be generalized  
further and reduced to generic rules that only require RDF support and  
nothing else. My request for an OWL.owl file is in exactly the same  
spirit.


 > This is clearly a fairly strong technical disagreement, one which we
 > are unlikely to come to agreement on.

I hope not. I don't see a strong technical disagreement here, just  
different use cases.

Regards,
Holger


[1] http://lists.w3.org/Archives/Public/public-owl-comments/2009Jul/0012.html
[2] http://lists.w3.org/Archives/Public/public-owl-comments/2009Jul/0013.html
[3] http://lists.owldl.com/pipermail/pellet-users/2007-August/001809.html



On Jul 13, 2009, at 2:38 PM, Holger Knublauch wrote:

Hi Michael,

hmm, I am a bit surprised.  Assuming that OWL 2 is supposed to become  
the next version of the OWL namespace, then what were the plans to  
upgrade those online documents of the OWL vocabulary?  Shouldn't such  
an RDF file have been a primary deliverable of the working group?   
After all, OWL is part of the Semantic Web stack in which linked data  
principles such as dereferencable URIs play some role?

I'll post my request to the comments list as you propose.

Thanks
Holger



Michael Schneider wrote:
Hi Holger!
owl.owl basically determines the domains and ranges of the OWL built-in
properties, the super classes of the built-in classes, and the like.  
What
IMO comes closest to owl.owl in the OWL 2 spec is the informative  
Section on
"Axiomatic Triples" in the OWL 2 RDF-Based Semantics:
<http://www.w3.org/TR/2009/CR-owl2-rdf-based-semantics-20090611/#Appendix 
:_A
xiomatic_Triples_.28Informative.29>
But this section only describes how to receive the different triples, it
doesn't list them explicitly.
If you would like to see the triples explicitly mentioned in the OWL 2  
spec,
you can send a request to the OWL WG's official comment list:
  <public-owl-comments@w3.org>
Cheers,
Michael
-----Original Message-----
From: public-owl-dev-request@w3.org [mailto:public-owl-dev-
request@w3.org] On Behalf Of Holger Knublauch
Sent: Monday, July 13, 2009 10:55 PM
To: public-owl-dev@w3.org
Subject: Re: OWL 2 -- Call for Implementations, new Drafts

Yes, exactly.

Holger


On Jul 13, 2009, at 1:48 PM, Michael Schneider wrote:

Hi Holger!

Do you mean an equivalent to "owl.owl", the schema given in

<http://www.w3.org/TR/owl-ref/#appB>

?

Cheers,
Michael

-----Original Message-----
From: public-owl-dev-request@w3.org [mailto:public-owl-dev-
request@w3.org] On Behalf Of Holger Knublauch
Sent: Monday, July 13, 2009 10:06 PM
To: public-owl-dev@w3.org
Subject: Re: OWL 2 -- Call for Implementations, new Drafts

All,

does anyone have a link to a file containing the new OWL 2 triples
(in
some RDF serialization)? I am looking for the equivalent of the file
that is on the OWL namespace address but including the new triples.
This file would make an OWL 2 "implementation" for RDF aware tools
basically a no-op :)  But I didn't find it among the list of
deliverables...

Thanks
Holger

--
Dipl.-Inform. Michael Schneider
Research Scientist, Dept. Information Process Engineering (IPE)
Tel  : +49-721-9654-726
Fax  : +49-721-9654-727
Email: michael.schneider@fzi.de
WWW  : http://www.fzi.de/michael.schneider
=
======================================================================
FZI Forschungszentrum Informatik an der Universität Karlsruhe
Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
Tel.: +49-721-9654-0, Fax: +49-721-9654-959
Stiftung des bürgerlichen Rechts, Az 14-0563.1, RP Karlsruhe
Vorstand: Prof. Dr.-Ing. Rüdiger Dillmann, Dipl. Wi.-Ing. Michael
Flor,
Prof. Dr. Dr. h.c. Wolffried Stucky, Prof. Dr. Rudi Studer
Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus
=
======================================================================
--
Dipl.-Inform. Michael Schneider
Research Scientist, Dept. Information Process Engineering (IPE)
Tel  : +49-721-9654-726
Fax  : +49-721-9654-727
Email: michael.schneider@fzi.de
WWW  : http://www.fzi.de/michael.schneider
=======================================================================
FZI Forschungszentrum Informatik an der Universität Karlsruhe
Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
Tel.: +49-721-9654-0, Fax: +49-721-9654-959
Stiftung des bürgerlichen Rechts, Az 14-0563.1, RP Karlsruhe
Vorstand: Prof. Dr.-Ing. Rüdiger Dillmann, Dipl. Wi.-Ing. Michael Flor,
Prof. Dr. Dr. h.c. Wolffried Stucky, Prof. Dr. Rudi Studer
Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus
=======================================================================
Received on Tuesday, 21 July 2009 22:36:17 GMT

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