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RE: [Fwd: Re: Invitation for review of POWDER documents (Last Call)]

From: Michael Schneider <schneid@fzi.de>
Date: Mon, 27 Apr 2009 18:00:26 +0200
Message-ID: <0EF30CAA69519C4CB91D01481AEA06A001260213@judith.fzi.de>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: <public-owl-wg@w3.org>, <ivan@w3.org>
>-----Original Message-----
>From: public-owl-wg-request@w3.org [mailto:public-owl-wg-request@w3.org]
>On Behalf Of Peter F. Patel-Schneider
>Sent: Monday, April 27, 2009 4:02 PM
>To: ivan@w3.org
>Cc: public-owl-wg@w3.org
>Subject: Re: [Fwd: Re: Invitation for review of POWDER documents (Last
>What about the some restriction?  Was our response not entirely correct?
>It looks as if a some restriction would give the extra semantics that
>they appear to want, but I am having trouble reconstructing the correct

Hm, I now also believe that it should really be "some" instead of "all".
But, huh, this really isn't obvious from the text there!

I believe the idea is that every resource r may or may not have a property
hasIRI, telling the resource's IRI, e.g.

  ex:foo wdrs:hasIRI "http://www.example.org/foo"^^xsd:anyURI

Now, the "some" restriction exactly captures all those resources r that on
the one hand have such a hasIRI property attached, and where on the other
hand the value of that property equals one of the strings matching the
regular expression PATTERN. 

On the contrary, the "all" restriction would also capture all those
resources that do not have a hasIRI property attached at all. Certainly not
what they want.

I suggest that we ask them to clarify the intended meaning of "hasIRI". I
also believe that the semantic condition presented in §4.6 is broken, see my
today's private comment (it's mainly on section §4.3, but the problem is
basically the same):




>From: Ivan Herman <ivan@w3.org>
>Subject: [Fwd: Re: Invitation for review of POWDER documents (Last
>Date: Mon, 27 Apr 2009 13:23:32 +0200
>> My intention is to answer 'yes' to all the points, ie, that the WG is
>> satisfied. Any objections to that?
>> Ivan
>> -------- Original Message --------
>> Subject: Re: Invitation for review of POWDER documents (Last Call)
>> Date: Mon, 27 Apr 2009 14:12:40 +0300
>> From: Stasinos Konstantopoulos <konstant@iit.demokritos.gr>
>> To: Ivan Herman <ivan@w3.org>
>> CC: Phil Archer <phil@philarcher.org>,	W3C OWL Working Group
>> <public-owl-wg@w3.org>
>> References: <49D9D592.9030201@philarcher.org>
>> Ivan, W3C-WG, hi.
>> On Apr 16, 2009, at 10:52 AM, Ivan Herman wrote:
>>> - The reference should be to XSD1.1 and not XSD2:
>>>      http://www.w3.org/TR/xmlschema11-2/
>>> - 'At the time of writing, the OWL-2' should say "OWL 2" (ie, no
>>> hyphen)
>>> - The reference to OWL 2 currently points to the OWL 2 Primer. We
>>> think
>>> it would be better if it pointed at the (new) OWL 2 Document
>>> http://www.w3.org/TR/owl2-overview/
>> All updated, thank you.
>>> - The semantic condition refers to rdfs:Resource for the domain of
>>> hasIRI. Although the description refers to an extension of the RDF
>>> semantics, it makes use of, say, owl:DatatypeProperty. Hence it may
>>> stylistically better to refer to owl:Thing.
>> I am leaning towards removing the domain triple altogether, as
>> it is obviously gratuitous.
>>> - The encoding of the condition in the example has several problems,
>>> partially due to some recent changes in OWL 2. These are:
>>>    - namespace changes (OWL 2 refers to xsd:pattern directly and not
>>> owl:pattern (OWL 2 reuses rdfs:Datatype instead of owl:datarange)
>> Updated.
>>>    - we also think that the type of restriction used is
>>> owl:hasValue should refer to a single individual and not to a
>>> datatype/datarange. Based on the rest of the POWDER semantics, what
>>> you
>>> probably have to use is owl:allValuesFrom, but this is something you
>>> have to decide, of course
>> Shouldn't it be owl:someValuesFrom to guarantee that the specified
>> value exists? Since hasIRI is functional, it also guarantees that all
>> values are also as expected. I am interested in OWL WG's reaction to
>> this.
>>>    - the RDF mapping of facets is based on a list of blank nodes
>>> instead of the approach used in the current code
>>> The first example (the second has similar structure) should look
>>> something like:
>>> <owl:Restriction>
>>>  <owl:onProperty rdf:resource="....#hasIRI"/>
>>>  <owl:allValuesFrom>
>>>    <rdfs:Datatype>
>>>      <owl:onDatatype rdf:resource="...#string"/>
>>>      <owl:withRestrictions rdf:parseType="Collection">
>>>        <rdf:Description>
>>>          <xsd:pattern rdf:datatype="...#string">PATTERN</xsd:pattern>
>>>        </rdf:Description>
>>>      </owl:withRestrictions>
>>>    <rdfs:Datatype>
>>>  </owl:allValuesFrom>
>>> </owl:Restriction>
>> Indeed, modulo the owl:allValuesFrom vs. owl:someValuesFrom issue.
>> Best,
>> Stasinos
>> --
>> Ivan Herman, W3C Semantic Web Activity Lead
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> PGP Key: http://www.ivan-herman.net/pgpkey.html
>> FOAF: http://www.ivan-herman.net/foaf.rdf

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
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Received on Monday, 27 April 2009 16:08:34 UTC

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