RE: A problem with HasKey in the functional-style syntax

Hi Boris!

I think your proposal will at least shuffle the properties. On the RDF side, object and data properties can occur in any order. But your proposal will say "all object properties first" for the Functional Style syntax. 

This isn't a problem from a semantic perspective, because the meaning of a key axiom does not depend on the ordering of the properties. But if someone prefers some "natural" ordering of the properties in a key axiom, then this ordering on the RDF side may get lost when, for example, editing the ontology with a Functional Syntax based editing tool.

My idea of "inlined declarations" would avoid this annoyance. :-) 

Michael

>-----Original Message-----
>From: public-owl-wg-request@w3.org [mailto:public-owl-wg-request@w3.org]
>On Behalf Of Ivan Herman
>Sent: Thursday, March 19, 2009 9:42 AM
>To: Boris Motik
>Cc: 'W3C OWL Working Group'
>Subject: Re: A problem with HasKey in the functional-style syntax
>
>HI Boris,
>
>just checking, to be sure:
>
>- this does affect the RDF Mapping, but only in the func syntax side.
>Ie, the RDF representation of HasKey does not change
>- the grammar rules for OWL RL should also be updated but not the RDF
>Rules
>
>Is that correct?
>
>Ivan
>
>Boris Motik wrote:
>> Hello,
>>
>> I'm sorry -- you are right; I misplaced the pipe symbol. It should
>have been
>> like this:
>>
>> HasKey := 'HasKey' '(' ClassExpression
>>     [ 'ObjectPropertyList' '(' { ObjectPropertyExpression } ')' ]
>>     [ 'DataPropertyList'   '(' { DataPropertyExpression   } ')' ]
>> ')'
>>
>> We should also add a restriction that there should be at least one
>(object or
>> data) property.
>>
>> This suggestion is motivated by the UML diagram. In fact, to get
>closer to UML,
>> we could do this:
>>
>> HasKey := 'HasKey' '(' ClassExpression
>>     [ 'ObjectProperties' '(' { ObjectPropertyExpression } ')' ]
>>     [ 'DataProperties'   '(' { DataPropertyExpression   } ')' ]
>> ')'
>>
>> I think I'd prefer not to repeat 'ObjectProperty' in front of each
>property. So
>> unless anyone objects, I'd go with the latter suggestion.
>>
>> Thanks again for catching this!
>>
>> Regards,
>>
>>  Boris
>>
>>> -----Original Message-----
>>> From: Michael Schneider [mailto:schneid@fzi.de]
>>> Sent: 18 March 2009 20:36
>>> To: Boris Motik
>>> Cc: W3C OWL Working Group
>>> Subject: RE: A problem with HasKey in the functional-style syntax
>>>
>>>> -----Original Message-----
>>>> From: public-owl-wg-request@w3.org [mailto:public-owl-wg-
>request@w3.org]
>>>> On Behalf Of Boris Motik
>>>> Sent: Wednesday, March 18, 2009 6:37 PM
>>>> To: 'W3C OWL Working Group'
>>>> Subject: A problem with HasKey in the functional-style syntax
>>>>
>>>> Hello,
>>>>
>>>> I've just noticed a problem in the functional-style syntax for
>HasKey.
>>>> The
>>>> current syntax is
>>>>
>>>> HasKey( CE P1 ... Pn )
>>>>
>>>> where Pi are either object or data properties. But this means that
>the
>>>> axiom is
>>>> not fully typed. Consider, for example, the following axiom:
>>>>
>>>> HasKey( a:MyClass a:MyProperty )
>>>>
>>>> >From this axiom alone, it is not clear whether a:MyProperty is an
>>>> object or a
>>>> data property. Effectively, this means that we haven't addressed
>>>> correctly the
>>>> comment by Matthew Horridge.
>>>>
>>>> My proposal for fixing this is to write the above axiom like this:
>>>>
>>>> HasKey( a:MyClass ObjectPropertyList( a:MyProperty ) )
>>>>
>>>> More generally, the grammar would be like this:
>>>>
>>>> HasKey := 'HasKey' '(' ClassExpression
>>>>    'ObjectPropertyList' '(' { ObjectPropertyExpression } ')' |
>>>>    'DataPropertyList'   '(' { DataPropertyExpression   } ')'
>>>> ')'
>>> I don't understand this proposal. It seems to only cover the special
>cases,
>>> where there are exclusively either object properties or data
>properties in
>>> the argument list. What about mixtures of object and data properties?
>>>
>>> I first also wondered what this does buy us (or Matthew) at all,
>since this
>>> doesn't make the HasKey axiom "typed". But I think what you mean is
>that the
>>> declarations will be at least "local" to the axiom here, and won't be
>spread
>>> around over the whole ontology, as it is currently the case. Is this
>right?
>>>
>>> Then, the obvious idea to me would be to generally allow for
>"inlined"
>>> entity declarations, as in
>>>
>>>   HasKey ( Class(CE) ObjectProperty(P1) DataProperty(P2)
>ObjectProperty(P3)
>>> DataProperty(P4) )
>>>
>>> One can allow this for every type of axiom, and make it mandatory in
>cases
>>> such as for the properties in HasKey axioms.
>>>
>>> Yes, I know, yet another larger change. But is there an alternative?
>(Maybe
>>> I totally miss the point here?)
>>>
>>> Best,
>>> Michael
>>>
>>> --
>>> 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
>>>
>=======================================================================
>>
>>
>>
>
>--
>
>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
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
=======================================================================