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Re: A proposal for clarifying the definitions of datatype maps, take II

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Wed, 29 Jul 2009 23:30:15 +0100
Message-Id: <3146FF00-28E2-41F1-B4CA-BB932691F815@comlab.ox.ac.uk>
Cc: Jim Hendler <hendler@cs.rpi.edu>, Boris Motik <boris.motik@comlab.ox.ac.uk>, "OWL 1.1" <public-owl-wg@w3.org>
To: Alan Ruttenberg <alanruttenberg@gmail.com>
Alan,

Getting rid of this MUST in Conformance is one of the main purposes  
of the cleanup -- the MUST was an ugly sticking plaster that was  
needed only in order to cover up the fact that Syntax didn't  
sufficiently constrain the OWL 2 Datatype map. Syntax now does this.  
As a result, we no longer need the sticking plaster.

Conformance now simply says that conformant systems have to support  
the language as defined in the spec -- which is clearly what it  
always should have said. Of course some analysis is required in order  
to understand the spec, but this is true for all parts of it and not  
just datatypes.

Regards,
Ian


On 29 Jul 2009, at 17:22, Alan Ruttenberg wrote:

> On Tue, Jul 28, 2009 at 6:39 PM, Ian
> Horrocks<ian.horrocks@comlab.ox.ac.uk> wrote:
>> The WG (including Ivan and Sandro) discussed and resolved on this  
>> already --
>> see [1]. What I was reporting was simply the completion of the  
>> relevant
>> action [2]. The rationale is that the change is only editorial,  
>> because we
>> didn't change anything w.r.t. the overall spec -- the MUST simply  
>> moved from
>> Conformance to Syntax.
>
> Hi Ian,
>
> But my point is that the MUST was lost in the process, as is confirmed
> by Boris' email. While it may be the case that the effect is the same,
> it now requires some inference to arrive at the conclusion.
>
> To be honest I would prefer if we had a MUST somewhere, even if it
> seems redundant on careful analysis.
>
> -Alan
>
>
>>
>> My understanding is that we will report all such changes in the PR  
>> versions
>> of the documents.
>>
>> Let me know if you think we need to do something more.
>>
>> Regards,
>> Ian
>>
>> [1] http://www.w3.org/2007/OWL/meeting/2009-07-01#resolution_2
>> [2] http://www.w3.org/2007/OWL/tracker/actions/344
>>
>>
>>
>> On 28 Jul 2009, at 22:20, Jim Hendler wrote:
>>
>>> I hate to be a stickler for process, but this seems like it is  
>>> slightly
>>> more than just a bug fix (esp. as it, appropriately, removes a  
>>> MUST clause)
>>> - to be clear, I think this is a good change and I think it does not
>>> invalidate a move to CR, but we should ask our team reps (Ivan  
>>> and Sandro)
>>> to make sure we are compliant with process and do whatever  
>>> notification we
>>> need to do (if any) so that we can move ahead -- I think it may  
>>> just need to
>>> be added as a note in the CR documentation (that we made this  
>>> clarifying
>>> change), but at this late date let's be sure to dot our i's and  
>>> cross our
>>> t's (as the expression goes)
>>>  -JH
>>>
>>>
>>> On Jul 28, 2009, at 6:09 AM, Ian Horrocks wrote:
>>>
>>>> It might be worth adding that this was exactly the motivation  
>>>> for the
>>>> clarification/cleanup. As things stood before, the concept  
>>>> language was
>>>> precisely defined in Syntax/Profiles, and Conformance simply  
>>>> said that
>>>> conformant systems had to support the concept language as  
>>>> defined in those
>>>> documents; in contrast the datatype language was relatively  
>>>> loosely defined
>>>> (or at least allowed for some variability), and Conformance  
>>>> "fixed" this by
>>>> stating that conformant systems must support all OWL 2  
>>>> datatypes. This was
>>>> clearly undesirable -- important parts of the language  
>>>> specification should
>>>> not be "hidden" in Conformance.
>>>>
>>>> The result of the clarification is that Syntax/Profiles now  
>>>> precisely
>>>> define the datatype part of the language just as for the concept  
>>>> part.
>>>> Conformance can thus simply say that conformant systems must  
>>>> support the
>>>> language as defined in Syntax/Profiles.
>>>>
>>>> Ian
>>>>
>>>>
>>>> On 28 Jul 2009, at 07:43, Boris Motik wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> While it is true that this sentence was removed, I don't think  
>>>>> that
>>>>> anything has
>>>>> been lost from the normative point of view.
>>>>>
>>>>> The Syntax document now defines in Section 4 the OWL 2 datatype  
>>>>> map as a
>>>>> fixed
>>>>> set of datatypes; then, in Section 5 it says that people can  
>>>>> use these
>>>>> datatypes
>>>>> in OWL 2 ontologies. Datatypes are now just like any other  
>>>>> construct:
>>>>> they are a
>>>>> fixed part of the language. Saying something like "an OWL 2  
>>>>> tool must
>>>>> support
>>>>> all OWL 2 datatypes" is thus tantamount to saying "an OWL 2  
>>>>> tool must
>>>>> support
>>>>> all OWL 2 class constructors".
>>>>>
>>>>> The sentence you refer to has been introduced because things  
>>>>> have not
>>>>> been like
>>>>> this earlier: the set of datatypes was not fixed and we initially
>>>>> allowed for a
>>>>> pick-and-mix approach. Since this is now completely gone from  
>>>>> all parts
>>>>> of the
>>>>> Syntax document (as well as the other documents), I really  
>>>>> don't think
>>>>> anything
>>>>> special needs to be said about the support for datatypes: they  
>>>>> need to
>>>>> be
>>>>> supported in their entirety just like any other part of the  
>>>>> language.
>>>>>
>>>>> Regards,
>>>>>
>>>>>        Boris
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: public-owl-wg-request@w3.org
>>>>>> [mailto:public-owl-wg-request@w3.org] On
>>>>>> Behalf Of Alan Ruttenberg
>>>>>> Sent: 28 July 2009 04:30
>>>>>> To: Ian Horrocks
>>>>>> Cc: OWL 1.1; Boris Motik
>>>>>> Subject: Re: A proposal for clarifying the definitions of  
>>>>>> datatype
>>>>>> maps, take
>>>>>> II
>>>>>>
>>>>>> I may have missed something, however it appears that these  
>>>>>> changes,
>>>>>> while clarifying the meaning of the datatypes in the OWL 2  
>>>>>> Datatype
>>>>>> map, also remove a strong constraint - namely that OWL 2 DL  
>>>>>> tools MUST
>>>>>> support all the types in that datatype map.
>>>>>>
>>>>>> In particular:
>>>>>>
>>>>>> "OWL 2 tools <em title="MUST in RFC 2119 context"
>>>>>> class="RFC2119">MUST</em> support the OWL 2 datatype map  
>>>>>> described in
>>>>>> the rest of this section. "
>>>>>>
>>>>>> has been removed.
>>>>>>
>>>>>> I don't believe that Boris' original note suggested this would  
>>>>>> be the
>>>>>> case.
>>>>>>
>>>>>> I'd appreciate some clarification on this matter.
>>>>>>
>>>>>> Thanks,
>>>>>> Alan
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Sun, Jul 26, 2009 at 4:52 PM, Ian
>>>>>> Horrocks<ian.horrocks@comlab.ox.ac.uk> wrote:
>>>>>>>
>>>>>>> As you will recall, the WG approved Boris's proposal during  
>>>>>>> the 1st
>>>>>>> July
>>>>>>> teleconf [1]. Completing the necessary work has taken a while --
>>>>>>> entirely my
>>>>>>> fault for being slow to do the necessary work on Conformance.
>>>>>>>
>>>>>>> To summarise, Boris has clarified the definition of datatypes  
>>>>>>> and the
>>>>>>> OWL
>>>>>>> datatype map in Syntax. As a result, Conformance no longer  
>>>>>>> needs to
>>>>>>> specify
>>>>>>> constraints on datatypes and the datatype map (e.g., that  
>>>>>>> conformant
>>>>>>> tools
>>>>>>> must use the OWL 2 datatype map) -- the datatypes that can  
>>>>>>> occur in
>>>>>>> (profile) documents and that must be supported by (profile)  
>>>>>>> tools are
>>>>>>> now
>>>>>>> explicitly defined in Syntax and Profiles. The relevant diffs  
>>>>>>> are:
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> http://www.w3.org/2007/OWL/wiki/index.php? 
>>>>>> title=Syntax&diff=24783&oldid=24704
>>>>>>>
>>>>>>
>>>>>> http://www.w3.org/2007/OWL/wiki/index.php? 
>>>>>> title=Syntax&diff=24850&oldid=24798
>>>>>>>
>>>>>>
>>>>>> http://www.w3.org/2007/OWL/wiki/index.php? 
>>>>>> title=Conformance&diff=24942&oldid=2
>>>>>> 4877
>>>>>>>
>>>>>>> Please let us know ASAP if you have any comments w.r.t. these  
>>>>>>> changes.
>>>>>>>
>>>>>>> Regards,
>>>>>>> Ian
>>>>>>>
>>>>>>> [1] http://www.w3.org/2007/OWL/meeting/2009-07-01#resolution_2
>>>>>>>
>>>>>>>
>>>>>>> On 29 Jun 2009, at 14:33, Boris Motik wrote:
>>>>>>>
>>>>>>>> Hello,
>>>>>>>>
>>>>>>>> In April I've sent around the following e-mail, in which I've
>>>>>>>> proposed to
>>>>>>>> clarify certain definitions surrounding datatype maps:
>>>>>>>>
>>>>>>>> http://lists.w3.org/Archives/Public/public-owl-wg/2009Apr/ 
>>>>>>>> 0454.html
>>>>>>>>
>>>>>>>> Please refer to my original e-mail for the details; in  
>>>>>>>> short, the
>>>>>>>> idea is
>>>>>>>> to
>>>>>>>> remove certain discrepancies between Conformance and the  
>>>>>>>> rest of the
>>>>>>>> documents,
>>>>>>>> with Conformance being taken as a guideline.
>>>>>>>>
>>>>>>>> I haven't pushed this forward earlier because we were  
>>>>>>>> getting ready
>>>>>>>> to go
>>>>>>>> into
>>>>>>>> CR. Since we've successfully reached that milestone, now  
>>>>>>>> seems like a
>>>>>>>> perfect
>>>>>>>> time for improving the spec. Therefore, unless someone  
>>>>>>>> objects, I
>>>>>>>> would
>>>>>>>> make a
>>>>>>>> few editorial changes to the spec and inform the WG of the  
>>>>>>>> outcome.
>>>>>>>>
>>>>>>>> Regards,
>>>>>>>>
>>>>>>>>      Boris
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>> We choose to go to the moon in this decade and do the other  
>>> things, not
>>> because they are easy, but because they are hard - John F.  
>>> Kennedy, Sept 12,
>>> 1962
>>>
>>> Prof James Hendler
>>>  http://www.cs.rpi.edu/~hendler, @jahendler, twitter
>>> Tetherless World Constellation Chair
>>> Computer Science Dept
>>> Rensselaer Polytechnic Institute, Troy NY 12180
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
Received on Wednesday, 29 July 2009 22:31:04 GMT

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