OWL 2 -- Call for Implementations, new Drafts

[Sandro Hawke]

OWL 2, a compatible extension to OWL 1, is now a W3C Candidate
Recommendation.  This means that if you are a developer of an OWL
system, it may be a good time to start adopting OWL 2.  The design is
not likely to change now, and this is the time to tell us about any
problems that come up during implementation.  Also, the primer, quick
reference, and new features document, (which are non-normative documents
intended to help people understand OWL) are now at Last Call, indicating
we think they are essentially done.

A good place to start is the OWL 2 Document Overview:

   http://www.w3.org/TR/owl2-overview/

It gives a brief overview of OWL2, and offers a guide to each of the
other OWL 2 documents.  We'll be tracking what we know of
implementations here:

   http://www.w3.org/2007/OWL/wiki/Implementations


Please send implementation reports and any other comments to
public-owl-comments@... by 30 July.  Soon after that, we expect to
proceed to Proposed Recommendation and Recommendation.  Discussion
among OWL developers is welcome at public-owl-dev@....

  -- Sandro Hawke, W3C Staff Contact, OWL Working Group

[AzamatAbdoullaev]

SH: "we expect to proceed to Proposed Recommendation and Recommendation."



What i like with the OWL 0, its high understanding of the subject: "Ontology
is a term borrowed from philosophy that refers to the science of describing
the kinds of entities in the world and how they are related."

And what i am missing with the OWL 2, the former definition, belittled as:
"Ontologies are formalized vocabularies of terms, often covering a specific
domain and shared by a community of users. They specify the definitions of
terms by describing their relationships with other terms in the ontology."
http://www.w3.org/TR/owl2-overview/

Here are more inconsistencies. "OWL 2 is a knowledge representation
language, designed to formulate, exchange and reason with knowledge about a
domain of interest...these basic notions: Axioms: the basic statements that
an OWL ontology expresses; Entities: elements used to refer to real-world
objects; Expressions: combinations of entities to form complex descriptions
from basic ones".

Let's see what entities are here. "All atomic constituents of statements, be
they objects (John, Mary), categories (female) or relations (married) are
called entities. In OWL 2, we denote objects as individuals, categories as
classes and relations as properties."

Are all these entities, individuals, classes, properties, entities of
real-world objects?

In the primer there is a heading. "Advanced class relationships: (class)
intersection, union and complement",
http://www.w3.org/TR/2009/WD-owl2-primer-20090611/

If somebody proposing a modeling language "designed to represent rich and
complex knowledge about things, groups of things, and relations between
things", it would be wise to distinguish the formal set theory operations,
f: SxS to S, from the relationships proper, R = SxS, where S is an unordered
collection of distinct elements (members, objects, entities), and R is an
ordered collection of distinct elements. The samples of pairing
relationships between sets (classes) are "is equivalent of", "is a
complement of", "is a subset of", "has the same cardinality", etc., between
elements "is equal to", "is less than", etc. In algebra of relation, we do
operations (binary) on relations (binary).

I mentioned before with other standard candidate and have to repeat again:
"Strongly believe any standardization work involving ontology and semantic
technology standards needs a deep fundamental research tested with effective
knowledge and content systems and real world applications."

I'd add: an open public debate as far as "the W3C OWL 2 Web Ontology
Language (OWL) is a Semantic Web language...'', and as far as standards are
today may go as binding laws, both for humans and machines.



Azamat Abdoullaev

http://www.semanticwww.com

http://www.eis.com.cy




----- Original Message -----
From: "Sandro Hawke" <sandro@...>
To: <semantic-web@...>; <public-owl-dev@...>
Sent: Monday, June 15, 2009 8:14 PM
Subject: OWL 2 -- Call for Implementations, new Drafts

> OWL 2, a compatible extension to OWL 1, is now a W3C Candidate
> Recommendation.  This means that if you are a developer of an OWL
> system, it may be a good time to start adopting OWL 2.  The design is
> not likely to change now, and this is the time to tell us about any
> problems that come up during implementation.  Also, the primer, quick
> reference, and new features document, (which are non-normative documents
> intended to help people understand OWL) are now at Last Call, indicating
> we think they are essentially done.
>
> A good place to start is the OWL 2 Document Overview:
>
>   http://www.w3.org/TR/owl2-overview/
>
> It gives a brief overview of OWL2, and offers a guide to each of the
> other OWL 2 documents.  We'll be tracking what we know of
> implementations here:
>
>   http://www.w3.org/2007/OWL/wiki/Implementations
>
>
> Please send implementation reports and any other comments to
> public-owl-comments@... by 30 July.  Soon after that, we expect to
> proceed to Proposed Recommendation and Recommendation.  Discussion
> among OWL developers is welcome at public-owl-dev@....
>
>  -- Sandro Hawke, W3C Staff Contact, OWL Working Group
>
>

[Sandro Hawke]

> SH: "we expect to proceed to Proposed Recommendation and Recommendation."
>
>
>
> What i like with the OWL 0, its high understanding of the subject: "Ontology
> is a term borrowed from philosophy that refers to the science of describing
> the kinds of entities in the world and how they are related."
>
> And what i am missing with the OWL 2, the former definition, belittled as:
> "Ontologies are formalized vocabularies of terms, often covering a specific
> domain and shared by a community of users. They specify the definitions of
> terms by describing their relationships with other terms in the ontology."
> http://www.w3.org/TR/owl2-overview/
>
> Here are more inconsistencies. "OWL 2 is a knowledge representation
> language, designed to formulate, exchange and reason with knowledge about a
> domain of interest...these basic notions: Axioms: the basic statements that
> an OWL ontology expresses; Entities: elements used to refer to real-world
> objects; Expressions: combinations of entities to form complex descriptions
> from basic ones".
>
> Let's see what entities are here. "All atomic constituents of statements, be
> they objects (John, Mary), categories (female) or relations (married) are
> called entities. In OWL 2, we denote objects as individuals, categories as
> classes and relations as properties."
>
> Are all these entities, individuals, classes, properties, entities of
> real-world objects?
>
> In the primer there is a heading. "Advanced class relationships: (class)
> intersection, union and complement",
> http://www.w3.org/TR/2009/WD-owl2-primer-20090611/
>
> If somebody proposing a modeling language "designed to represent rich and
> complex knowledge about things, groups of things, and relations between
> things", it would be wise to distinguish the formal set theory operations,
> f: SxS to S, from the relationships proper, R = SxS, where S is an unordered
> collection of distinct elements (members, objects, entities), and R is an
> ordered collection of distinct elements. The samples of pairing
> relationships between sets (classes) are "is equivalent of", "is a
> complement of", "is a subset of", "has the same cardinality", etc., between
> elements "is equal to", "is less than", etc. In algebra of relation, we do
> operations (binary) on relations (binary).
>
> I mentioned before with other standard candidate and have to repeat again:
> "Strongly believe any standardization work involving ontology and semantic
> technology standards needs a deep fundamental research tested with effective
> knowledge and content systems and real world applications."
>
> I'd add: an open public debate as far as "the W3C OWL 2 Web Ontology
> Language (OWL) is a Semantic Web language...'', and as far as standards are
> today may go as binding laws, both for humans and machines.

While the Working Group is interested in feedback, we do ask that people
send their comments to our public comments list if they want us to read
them, discuss them as a group, and reply.  (Also, please do NOT cross
post to that list, since it may cause other people to accidentally
submit comments if they reply to you.)  It helps if the comments suggest
specific, practical things we should do.

Of course, if you just meant this as a public discussion item, that's
fine.

(My apologies for cross posting, but I thought it was important to
clarify the comment procedure in all the places this message was
posted.)

     - Sandro

> Azamat Abdoullaev
>
> http://www.semanticwww.com
>
> http://www.eis.com.cy
>
>
>
>
> ----- Original Message -----
> From: "Sandro Hawke" <sandro@...>
> To: <semantic-web@...>; <public-owl-dev@...>
> Sent: Monday, June 15, 2009 8:14 PM
> Subject: OWL 2 -- Call for Implementations, new Drafts
>
>
> > OWL 2, a compatible extension to OWL 1, is now a W3C Candidate
> > Recommendation.  This means that if you are a developer of an OWL
> > system, it may be a good time to start adopting OWL 2.  The design is
> > not likely to change now, and this is the time to tell us about any
> > problems that come up during implementation.  Also, the primer, quick
> > reference, and new features document, (which are non-normative documents
> > intended to help people understand OWL) are now at Last Call, indicating
> > we think they are essentially done.
> >
> > A good place to start is the OWL 2 Document Overview:
> >
> >   http://www.w3.org/TR/owl2-overview/
> >
> > It gives a brief overview of OWL2, and offers a guide to each of the
> > other OWL 2 documents.  We'll be tracking what we know of
> > implementations here:
> >
> >   http://www.w3.org/2007/OWL/wiki/Implementations
> >
> >
> > Please send implementation reports and any other comments to
> > public-owl-comments@... by 30 July.  Soon after that, we expect to
> > proceed to Proposed Recommendation and Recommendation.  Discussion
> > among OWL developers is welcome at public-owl-dev@....
> >
> >  -- Sandro Hawke, W3C Staff Contact, OWL Working Group
> >
> >

[AzamatAbdoullaev]

SH: While the Working Group is interested in feedback, we do ask that people
send their comments to our public comments list if they want us to read
them, discuss them as a group, and reply.  (Also, please do NOT cross post
to that list, since it may cause other people to accidentally
submit comments if they reply to you.)  It helps if the comments suggest
specific, practical things we should do."

OK, without the cross-posting. Now what i tried to hint several times in a
soft way. With all my esteem to all its contributers and editors,
http://www.w3.org/TR/owl2-profiles/, in my humble but frank opinion, the
project, if not foundered, is certainly far away from the status of being a
standard, even "recommended standard", both in its parts and in the whole.
As an excuse, it must be mentioned that this group faced more complex task:
to merge different pieces into a single whole. For each part of work, a
listing of principal discrepancies and inconsistences and contradictories
could be presented, with one pragmatic suggestion: since it is a
time-consuming job to read all these pieces and bits, w3c could assign the
critical report to our company in due course. The knowledge of ontology and
semantics applied leaves much to be desired, and insisting on this version
will do nothing but harm the idea of semantic web, imho.

Azamat Abdoullaev
EIS Encyclopedic Intelligent Systems Ltd
http://www.standardontology.com

----- Original Message -----
From: "Sandro Hawke" <sandro@...>
To: "Azamat" <abdoul@...>
Cc: "'SW-forum'" <semantic-web@...>; "[ontolog-forum] "
<ontolog-forum@...>; <public-owl-dev@...>
Sent: Wednesday, June 17, 2009 3:06 AM
Subject: Re: OWL 2 -- Call for Implementations, new Drafts

>
>> SH: "we expect to proceed to Proposed Recommendation and Recommendation."
>>
>>
>>
>> What i like with the OWL 0, its high understanding of the subject:
>> "Ontology
>> is a term borrowed from philosophy that refers to the science of
>> describing
>> the kinds of entities in the world and how they are related."
>>
>> And what i am missing with the OWL 2, the former definition, belittled
>> as:
>> "Ontologies are formalized vocabularies of terms, often covering a
>> specific
>> domain and shared by a community of users. They specify the definitions
>> of
>> terms by describing their relationships with other terms in the
>> ontology."
>> http://www.w3.org/TR/owl2-overview/
>>
>> Here are more inconsistencies. "OWL 2 is a knowledge representation
>> language, designed to formulate, exchange and reason with knowledge about
>> a
>> domain of interest...these basic notions: Axioms: the basic statements
>> that
>> an OWL ontology expresses; Entities: elements used to refer to real-world
>> objects; Expressions: combinations of entities to form complex
>> descriptions
>> from basic ones".
>>
>> Let's see what entities are here. "All atomic constituents of statements,
>> be
>> they objects (John, Mary), categories (female) or relations (married) are
>> called entities. In OWL 2, we denote objects as individuals, categories
>> as
>> classes and relations as properties."
>>
>> Are all these entities, individuals, classes, properties, entities of
>> real-world objects?
>>
>> In the primer there is a heading. "Advanced class relationships: (class)
>> intersection, union and complement",
>> http://www.w3.org/TR/2009/WD-owl2-primer-20090611/
>>
>> If somebody proposing a modeling language "designed to represent rich and
>> complex knowledge about things, groups of things, and relations between
>> things", it would be wise to distinguish the formal set theory
>> operations,
>> f: SxS to S, from the relationships proper, R = SxS, where S is an
>> unordered
>> collection of distinct elements (members, objects, entities), and R is an
>> ordered collection of distinct elements. The samples of pairing
>> relationships between sets (classes) are "is equivalent of", "is a
>> complement of", "is a subset of", "has the same cardinality", etc.,
>> between
>> elements "is equal to", "is less than", etc. In algebra of relation, we
>> do
>> operations (binary) on relations (binary).
>>
>> I mentioned before with other standard candidate and have to repeat
>> again:
>> "Strongly believe any standardization work involving ontology and
>> semantic
>> technology standards needs a deep fundamental research tested with
>> effective
>> knowledge and content systems and real world applications."
>>
>> I'd add: an open public debate as far as "the W3C OWL 2 Web Ontology
>> Language (OWL) is a Semantic Web language...'', and as far as standards
>> are
>> today may go as binding laws, both for humans and machines.
>
> While the Working Group is interested in feedback, we do ask that people
> send their comments to our public comments list if they want us to read
> them, discuss them as a group, and reply.  (Also, please do NOT cross
> post to that list, since it may cause other people to accidentally
> submit comments if they reply to you.)  It helps if the comments suggest
> specific, practical things we should do.
>
> Of course, if you just meant this as a public discussion item, that's
> fine.
>
> (My apologies for cross posting, but I thought it was important to
> clarify the comment procedure in all the places this message was
> posted.)
>
>     - Sandro
>
>> Azamat Abdoullaev
>>
>> http://www.semanticwww.com
>>
>> http://www.eis.com.cy
>>
>>
>>
>>
>> ----- Original Message -----
>> From: "Sandro Hawke" <sandro@...>
>> To: <semantic-web@...>; <public-owl-dev@...>
>> Sent: Monday, June 15, 2009 8:14 PM
>> Subject: OWL 2 -- Call for Implementations, new Drafts
>>
>>
>> > OWL 2, a compatible extension to OWL 1, is now a W3C Candidate
>> > Recommendation.  This means that if you are a developer of an OWL
>> > system, it may be a good time to start adopting OWL 2.  The design is
>> > not likely to change now, and this is the time to tell us about any
>> > problems that come up during implementation.  Also, the primer, quick
>> > reference, and new features document, (which are non-normative
>> > documents
>> > intended to help people understand OWL) are now at Last Call,
>> > indicating
>> > we think they are essentially done.
>> >
>> > A good place to start is the OWL 2 Document Overview:
>> >
>> >   http://www.w3.org/TR/owl2-overview/
>> >
>> > It gives a brief overview of OWL2, and offers a guide to each of the
>> > other OWL 2 documents.  We'll be tracking what we know of
>> > implementations here:
>> >
>> >   http://www.w3.org/2007/OWL/wiki/Implementations
>> >
>> >
>> > Please send implementation reports and any other comments to
>> > public-owl-comments@... by 30 July.  Soon after that, we expect to
>> > proceed to Proposed Recommendation and Recommendation.  Discussion
>> > among OWL developers is welcome at public-owl-dev@....
>> >
>> >  -- Sandro Hawke, W3C Staff Contact, OWL Working Group
>> >
>> >

[jos.deroo]

Sandro,

OWL 2 is excellent work, really and I more than appreciate all the hard work
of the whole group!
In the minimal spare time that I collect I am trying to implement some pieces
of OWL 2 as in http://eulersharp.sourceforge.net/2003/03swap/eye-owl2.html
So far the experience is positive and I will try to extend it and combine it with
the rest of our work.

Thanks and we can work it out :-)

Kind regards,

Jos De Roo | Agfa HealthCare
Senior Researcher | HE/Advanced Clinical Applications Research
T  [phone]
http://www.agfa.com/w3c/jdroo/

Quadrat NV, Kortrijksesteenweg 157, 9830 Sint-Martens-Latem, Belgium
http://www.agfa.com/healthcare

Sandro Hawke <sandro@...>
Sent by: semantic-web-request@...

06/15/2009 07:14 PM

To	semantic-web@..., public-owl-dev@...
cc
Subject	OWL 2 -- Call for Implementations, new Drafts

OWL 2, a compatible extension to OWL 1, is now a W3C Candidate
Recommendation.  This means that if you are a developer of an OWL
system, it may be a good time to start adopting OWL 2.  The design is
not likely to change now, and this is the time to tell us about any
problems that come up during implementation.  Also, the primer, quick
reference, and new features document, (which are non-normative documents
intended to help people understand OWL) are now at Last Call, indicating
we think they are essentially done.

A good place to start is the OWL 2 Document Overview:

  http://www.w3.org/TR/owl2-overview/

It gives a brief overview of OWL2, and offers a guide to each of the
other OWL 2 documents.  We'll be tracking what we know of
implementations here:

  http://www.w3.org/2007/OWL/wiki/Implementations


Please send implementation reports and any other comments to
public-owl-comments@... by 30 July.  Soon after that, we expect to
proceed to Proposed Recommendation and Recommendation.  Discussion
among OWL developers is welcome at public-owl-dev@....

 -- Sandro Hawke, W3C Staff Contact, OWL Working Group

[Holger Knublauch]

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

[Michael Schneider-6]

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@... [mailto:public-owl-dev-
>request@...] On Behalf Of Holger Knublauch
>Sent: Monday, July 13, 2009 10:06 PM
>To: public-owl-dev@...
>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  : [phone]
Fax  : [phone]
Email: michael.schneider@...
WWW  : http://www.fzi.de/michael.schneider
=======================================================================
FZI Forschungszentrum Informatik an der Universität Karlsruhe
Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
Tel.: [phone], Fax: [phone]
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
=======================================================================

[Holger Knublauch]

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@... [mailto:public-owl-dev-
>> request@...] On Behalf Of Holger Knublauch
>> Sent: Monday, July 13, 2009 10:06 PM
>> To: public-owl-dev@...
>> 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  : [phone]
> Fax  : [phone]
> Email: michael.schneider@...
> WWW  : http://www.fzi.de/michael.schneider
> =
> ======================================================================
> FZI Forschungszentrum Informatik an der Universität Karlsruhe
> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
> Tel.: [phone], Fax: [phone]
> 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
> =
> ======================================================================

[Peter Haase-2]

Hi,

you can find the OWL 2 metamodel in various formats (including EMOF, OWL)
at http://ontoware.org/frs/?group_id=31
The version is from 2008-11-09.
There are likely some differences to the candidate recommendation.
I was planning to do an update when OWL 2 becomes recommendation. If there
is interest, I could possibly do it before.

Regards,
Peter

> -----Ursprüngliche Nachricht-----
> Von: public-owl-dev-request@... [mailto:public-owl-dev-
> request@...] Im Auftrag von Holger Knublauch
> Gesendet: Montag, 13. Juli 2009 22:55
> An: public-owl-dev@...
> Betreff: 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@... [mailto:public-owl-dev-
> >> request@...] On Behalf Of Holger Knublauch
> >> Sent: Monday, July 13, 2009 10:06 PM
> >> To: public-owl-dev@...
> >> 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  : [phone]
> > Fax  : [phone]
> > Email: michael.schneider@...
> > WWW  : http://www.fzi.de/michael.schneider
> > =
> >
> ======================================================================
> > FZI Forschungszentrum Informatik an der Universität Karlsruhe
> > Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
> > Tel.: [phone], Fax: [phone]
> > 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
> > =
> >
> ======================================================================
>

[Michael Schneider-6]

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@...>

Cheers,
Michael

>-----Original Message-----
>From: public-owl-dev-request@... [mailto:public-owl-dev-
>request@...] On Behalf Of Holger Knublauch
>Sent: Monday, July 13, 2009 10:55 PM
>To: public-owl-dev@...
>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@... [mailto:public-owl-dev-
>>> request@...] On Behalf Of Holger Knublauch
>>> Sent: Monday, July 13, 2009 10:06 PM
>>> To: public-owl-dev@...
>>> 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  : [phone]
>> Fax  : [phone]
>> Email: michael.schneider@...
>> WWW  : http://www.fzi.de/michael.schneider
>> =
>> ======================================================================
>> FZI Forschungszentrum Informatik an der Universität Karlsruhe
>> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
>> Tel.: [phone], Fax: [phone]
>> 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  : [phone]
Fax  : [phone]
Email: michael.schneider@...
WWW  : http://www.fzi.de/michael.schneider
=======================================================================
FZI Forschungszentrum Informatik an der Universität Karlsruhe
Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
Tel.: [phone], Fax: [phone]
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
=======================================================================

[Holger Knublauch]

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@...>
>
> Cheers,
> Michael
>
>> -----Original Message-----
>> From: public-owl-dev-request@... [mailto:public-owl-dev-
>> request@...] On Behalf Of Holger Knublauch
>> Sent: Monday, July 13, 2009 10:55 PM
>> To: public-owl-dev@...
>> 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@... [mailto:public-owl-dev-
>>>> request@...] On Behalf Of Holger Knublauch
>>>> Sent: Monday, July 13, 2009 10:06 PM
>>>> To: public-owl-dev@...
>>>> 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  : [phone]
>>> Fax  : [phone]
>>> Email: michael.schneider@...
>>> WWW  : http://www.fzi.de/michael.schneider
>>> =
>>> ======================================================================
>>> FZI Forschungszentrum Informatik an der Universität Karlsruhe
>>> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
>>> Tel.: [phone], Fax: [phone]
>>> 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  : [phone]
> Fax  : [phone]
> Email: michael.schneider@...
> WWW  : http://www.fzi.de/michael.schneider
> =======================================================================
> FZI Forschungszentrum Informatik an der Universität Karlsruhe
> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
> Tel.: [phone], Fax: [phone]
> 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
> =======================================================================
>

[Ivan Herman-2]

Peter,

personally, I believe it would be very useful to have an updated version
of this and not wait until OWL 2 becomes a Rec.

Thanks

Ivan

Peter Haase wrote:

> Hi,
>
> you can find the OWL 2 metamodel in various formats (including EMOF, OWL)
> at http://ontoware.org/frs/?group_id=31
> The version is from 2008-11-09.
> There are likely some differences to the candidate recommendation.
> I was planning to do an update when OWL 2 becomes recommendation. If there
> is interest, I could possibly do it before.
>
> Regards,
> Peter
>
>> -----Ursprüngliche Nachricht-----
>> Von: public-owl-dev-request@... [mailto:public-owl-dev-
>> request@...] Im Auftrag von Holger Knublauch
>> Gesendet: Montag, 13. Juli 2009 22:55
>> An: public-owl-dev@...
>> Betreff: 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@... [mailto:public-owl-dev-
>>>> request@...] On Behalf Of Holger Knublauch
>>>> Sent: Monday, July 13, 2009 10:06 PM
>>>> To: public-owl-dev@...
>>>> 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  : [phone]
>>> Fax  : [phone]
>>> Email: michael.schneider@...
>>> WWW  : http://www.fzi.de/michael.schneider
>>> =
>>>
>> ======================================================================
>>> FZI Forschungszentrum Informatik an der Universität Karlsruhe
>>> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
>>> Tel.: [phone], Fax: [phone]
>>> 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
>>> =
>>>
>> ======================================================================
>>
>
>
>
>

--

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: [phone]
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf

[Holger Knublauch-2]

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@...>
Cheers,
Michael
-----Original Message-----
From: public-owl-dev-request@... [mailto:public-owl-dev-
request@...] On Behalf Of Holger Knublauch
Sent: Monday, July 13, 2009 10:55 PM
To: public-owl-dev@...
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@... [mailto:public-owl-dev-
request@...] On Behalf Of Holger Knublauch
Sent: Monday, July 13, 2009 10:06 PM
To: public-owl-dev@...
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  : [phone]
Fax  : [phone]
Email: michael.schneider@...
WWW  : http://www.fzi.de/michael.schneider
=
======================================================================
FZI Forschungszentrum Informatik an der Universität Karlsruhe
Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
Tel.: [phone], Fax: [phone]
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  : [phone]
Fax  : [phone]
Email: michael.schneider@...
WWW  : http://www.fzi.de/michael.schneider
=======================================================================
FZI Forschungszentrum Informatik an der Universität Karlsruhe
Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
Tel.: [phone], Fax: [phone]
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
=======================================================================

[Bijan Parsia-3]

On 21 Jul 2009, at 23:22, Holger Knublauch wrote:

> 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.

I don't mean that reference to point to all the arguments I would  
mobilize against this practice, just as an indicator that this is an  
opinion of long standing.

In that particular thread, you'll see that people who depend on a  
(static) OWL file at the w3c are rather stuck. This is, itself, a  
problem, esp. when

> The other arguments just seem to repeat that importing SWRL is a bad  
> idea because you don't think this is a good practice.

It's bad practice because (not exhaustive):
        1) It pollutes the user defined vocabulary with the logical  
vocabulary which has many negative ramifications: e.g., it clutters  
the interface (sometimes severely); it can break reasoners and other  
manipulators (which can, of course, be solved by recognizing and  
filtering them out, but, uh, that means special case code anyway);  
there can be interations between my domain modelling and the  
"language" modeling (even at simple levels, for example, do I want my  
ontology stats to include individuals or classes from owl.owl?)

        2) It technically makes every document OWL Full in fairly strong  
ways. Yeah, I think it's a problem that if I'm not, myself, using OWL  
Full functionality that I'm forced into that extra expressivity. I  
want to pay only for what I use (as a modeller)

        3) owl.owl cannot provide a reasonably complete description of even  
the syntax of OWL, even if it uses all of OWL Full. At least, not in  
any sane way; certainly not how it is now. OWL is just not tuned for  
describing syntax constraints (contrast with XML Schema). Nothing  
wrong with that, but right tool for the job, etc.
        People get confused about that. I don't think we should encourage  
that confusion.

        4) It conflates specification with implementation. This is a problem  
I have with GRDDL (and even with using schema langauges for  
specification, although that's harder to resist).

        5) It (tends to) confuse syntax with semantics. Which I think is bad  
for users and newbie implementors.

        6) Generic editing of such things tends to be very bad experience for  
users, especially in GUIs. Editing swrl statements as abox stuff is a  
freaking nightmare in a Protege like interface.

Fortunately, it doesn't seem to be popular anymore. I see far fewer  
people advocating it than I did back in early 2000s.

> 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.

I accept that in your infrastructure you are set up so this works out  
ok. This makes owl.owl useful for you. But I imagine (and hope) that  
you are somewhat careful about built in vocabulary *anyway*.

For example, in swoop, at one point we just let people follow  
hyperlinks to the owl and rdf vocabulary. This triggered swoop to load  
those files. Almost always, that wasn't what was wanted (now there's  
three ontologies loaded when you really just are working on one). So  
we special cased all the builtin vocabulary to display help text.  
Human help text (derived from the owl reference).

Built-in vocabulary is special.

> Whether this makes the files OWL Full is from my point of view  
> completely irrelevant.

Because you already special case it in certain ways. Which is fine.  
But it doesn't make it fundamentally different from other  
implementation approaches.

But it's not just OWL Fullness. For example, having the vocabulary  
imported with axioms like would inherently demodularize the ontology.  
(Esp. for purely syntactic modularization algorithms.) Justifications  
would become way more complicated. Etc.

It's not just reasoning. And it's not just OWL Fullness per se. I can  
have a perfectly modular OWL Full file.

> If inference engines have problems with that, then they can happily  
> ignore those triples and imports.

So they have to special case it.

> 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.

Cleaner? I'm not sure how that's the case. But I guess this is an  
aesethetic judgement and our tastes can differ. But then this isn't a  
technical argument.

OWL is well defined and defined well by the specifications which, er,  
define it. owl.owl cannot *define* OWL.

RDF is well defined and defined well by the specs which define it.  
Even in RDF, the built-in vocabulary is treated specially (i.e., with  
additional semantic conditions).

Traditionally, e.g., in most logic, programming languages, what have  
you, orthogonality is valued and often what is appealed to when people  
say "cleanliness". owl.owl mishs things up. Sometimes, such mishing is  
considered neat (e.g., Lisp and Prolog's treatment of code as data and  
the ability to write metacircular interpreters), but these things are  
also tricky (it helps that with Lisp and Prolog they are actually  
expressive enough to define themselves; real implementations, even if  
bootstrapping, tend to separate things out).

As a user, I prefer the environment to have special knowledge of the  
language. Furthermore, I prefer that implementation details don't leak  
into my workaday situations. Obviously, by being a bit clever and with  
a bit of code, you can make this happen and still use owl.owl as you  
describe. But that's hardly the "for free" you've described.

> > 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

Well, we have to specify what we're implementing to be clear what the  
burden is. Some numbers might help.

People successfully build systems without it. Indeed, I would hazard  
that most OWL systems don't use it, even those based on RDF stores.  
The ones I know offhand are TBC and SWI Prolog.

Given the inherent incompleteness of such a file due to the expressive  
limitations of OWL or RDFS, it's hard to see how it would, in  
principle, be a big win. Compare with the XML Schema for OWL/XML  
which, while still not expressive enough to cover all of OWL's  
syntactic constraints, gets much closer. Compare with a BNF (for  
syntax).

Now, for the sort of application you support, the way you've  
implemented it, and the way you use the file, I rather suspect that an  
owl.owl file is helpful. But I think that's rather idiosyncratic. The  
SWRL tab is some evidence of how it can bring problems (because, for  
example, people believe it's the only way to implement SWRL support,  
or the best way, or they must use the central file even when buggy,  
etc.).

> and would significantly slow down any support for OWL 2 in our tools.

Well, heck, if it makes it *easier for you*, that's a relevant factor.  
Programming is heavily influenced by the comfort of the programmer in  
question. This is why I'm not fighting this per se. I want more OWL  
tools rather than fewer.

That's orthogonal to what I think about the general technical points  
and what I would recommend.

> So I do not share your view and claim the opposite (for our use  
> cases).

You don't think in some cases it's harmful? I don't see how that's  
supported by it working in your case. Similarly, it can work for you  
and still be misguided (all things considered).

Obviously it can be made to work...TBC and SWI Prolog are examples.

> > 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.

And why is this a problem? You also have to implement code that the  
working group does not deliver.

I get nervous about things people take as parallel specs. That hurts  
interop.

> 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.

Similarly, it seems to be perfectly reasonable for e.g., you and  
Michael to develop such a thing and open source it. Why does it need  
standardization esp. as it's really ersatz standardization?

(Again, the WG is going to do something here. I just don't see any  
good arguments for it.)

> > 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.

That's good. Lack of caching of things like DTDs is an ongoing problem  
for the W3C. (Which is another reason I think such things are bad  
practice.)

(e.g., http://hsivonen.iki.fi/no-dtd/)

> > 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.

Er...of course there is. (And swrl is on the OWL side.) I mean, the  
distinction between logical, builtin vocabulary and user vocabulary is  
a basic feature. Even with relatively uniform syntax (like triples)  
there's key distinctions both from a user and from a tool perspective.

And having some, key, vocabulary special cased is pretty harmless to  
an overall picture. After all, we do *standardize* stuff.  
Standardization is, almost essentially, a centralizing endeavor. We  
pick stuff we *want* to be standardized, and part of the  
infrastructure. So, there's no need to use mechanisms which are  
designed to accommodate a rather different situation.

> 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.

Not very much. As I've pointed out above.

I think you underestimate the amount of effort you've put in to making  
this work for drivimg TBC's interface. It would be interesting to  
analyze the source code to figure this out. If you'd like to  
experiment a bit with that I'd be happy to discuss that further. I.e.,  
how do we answer the questions:
1) What is owl.owl good for?
2) What infrastructure is necessary for it to be good for it?

> 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.

If your support needs are truly that minimal, then it's hardly a  
burden to add it manually. So I'm confused again.

> Of course, the OWL vocabulary is fundamentally different from the  
> point of view of OWL tools such as tableau inference engines.

Take the ontology statistics example. Should every count of the number  
of classes in an ontology include rdfs:class? As a user and someone  
who studies users, I can't see that that's helpful at all.

> 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.

? OWL RL definitely cannot be implemented in RDF alone. You definitely  
need a rule language. Which is quite a substantial leap over RDF alone.

> My request for an OWL.owl file is in exactly the same spirit.

In the OWL RL document, there are some informative rules provided as a  
guide for implementors. I personally wouldn't recommend them as such  
for a production system. Consider the entailment rules in the RDF  
semantics document---they are *terrible* as an implementation if taken  
blindly. DIfferent rule engines have different characteristic anyway.

> > 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.

Well, I hope our technical disagreement is relatively harmless. You  
certainly can do what I consider generically bad practice and do it  
with great success. As long as you don't serialize stuff with  
owl:imports owl.owl, we can largely interoperate without having to  
resolve our technical disagreements. Even then, I could work around  
that (by stripping them out).

We'll definitely offer different advice to new implementors...who will  
probably ignore us anyway :)

Cheers,
Bijan.

[Holger Knublauch-2]

Hi Bijan,

thanks for your very balanced response :) I appreciate that you  
understand where I am coming from, and I certainly also understand  
your view point. I don't want to respond to every single detail - this  
would just lead to an endless thread, and we all have work to do.

I agree that we need to make clear that people do not (again) start  
importing the owl.owl file into their domain models. This problem  
already exists because the current OWL namespace file is already  
there. So the question remains of what the OWL 2 working group will do  
with the old OWL.owl file. Either update it or drop it. Since it's a  
low hanging fruit, and since it makes life easier for many people  
(including myself and developers of any generic linked data browser or  
query tool) I don't see strong arguments against keeping an OWL (2)  
file there. The concerns that you seem to have are mostly "soft"  
issues such as educating people that this is not really a spec but  
just a set of RDF triples to describe the vocabulary. This appears to  
be very doable though.

Instead of owl:importing it, my assumption is that many semantic web  
tools will already have the OWL (and RDFS) namespaces somehow built-
in. In TBC we solve this using an implicit sub-graph that is  
automatically included into the display graph. We then have a list of  
URIs that are hidden in the class and properties trees by default, in  
particular some system properties that are really not meant to be used  
directly, such as owl:hasValue. For OWL 2, I will simply need to  
extend this list of properties and classes so that the UI does not get  
cluttered. This is minimal work.

There are several places where having the OWL triples is very helpful  
as it provides a basic skeleton. My usual example is the class tree  
structures where traversing the rdfs:subClassOf triples of the  
metaclasses is very useful. Overall the system triples make our code  
base much more model-driven and consistent. The price for this general  
solution is, as you state, that sometimes the generic solution is not  
enough and custom widgets, parsers or renderers are needed. This is  
particularly the case for blank node structures such as OWL  
restrictions. We have hard-coded some special handling for these into  
our tool, using a plugin mechanism. I will need to see in detail which  
new OWL 2 constructs require this, but from what I can tell so far  
there won't be a need to add much. At least, people can "see" and  
navigate to all OWL 2 resources consistently, including getting  
statistics (which simply could instances of each class including the  
metaclasses). Other tools may have different approaches to this, with  
more special handling of OWL constructs, but our starting point has  
been RDF(S) and so far this has been a very good choice (for us).

One of the places where I needed to hard-code against OWL vocabulary  
was to find "relevant" properties, i.e. the properties that shall by  
default show up on an instance form. With RDF(S) only, this would  
include all properties that have the type of the instance in their  
domain. With OWL, we also look for locally defined OWL restrictions. I  
may need to add a bit of that code for the new OWL 2 features, but the  
bulk of work has already been done for OWL 1. But other than that, you  
may be surprised of how little the OWL vocabulary is actually used in  
our code base. That's why - from my experience - we can treat OWL  
almost like any other ontology such as FOAF. Just like FOAF, OWL  
should therefore also have a vocabulary file at its base URI.

So overall, the OWL.owl file will help getting tools like ours  
started. We need to see what the hidden extra costs of adding OWL 2  
support will be, and this was also one of the points raised by earlier  
responses from TQ on OWL 2. People may gradually expect more and more  
"native" support for OWL 2 features and this might become a nightmare  
to support, especially given the huge number of OWL 2 features. We'll  
see how it goes once we start adding some OWL 2 support.

Cheers,
Holger