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Re: complementOf -> viewOf: proposed text

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Thu, 19 Jan 2012 09:29:16 +0000
Message-ID: <EMEW3|a7960e71b64ff5f5a43fcb1f73aa3772o0I9YK08L.Moreau|ecs.soton.ac.uk|4F17E26C.6050200@ecs.soton.ac.uk>
To: Paolo Missier <Paolo.Missier@ncl.ac.uk>
CC: Satya Sahoo <satya.sahoo@case.edu>, Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>, Paolo Missier <paolo.missier@newcastle.ac.uk>, "public-prov-wg@w3.org" <public-prov-wg@w3.org>
Hi Paolo and Satya,

I raised ISSUE-223 to that effect!
I agree with Paolo, we don't have a notion of class.

However ...

Jim seems to indicate that an entity can characterize multiple things 
....  If correct  (btw, that's not what prov-dm says!),
then seeing a entity as a class is not that a wrong point of view.

This said, where I strongly disagree with Satya is that we have made it 
clear that the attributes are not characterizing the entity.
(Resolution from a few weeks ago). Hence, in prov-dm terms, it's not 
because a given entity has a given prov-dm attribute
that it belongs to some class.

Luc

On 01/19/2012 09:17 AM, Paolo Missier wrote:
> Satya,
>
> but we don't have a notion of classes/instances in PROV. I remember 
> this being discussed early on and dismissed. As a result, you can't 
> use that framework so you can't make a distinction between the two 
> cases. It may be in our heads, but it's not in the language, right?
>
> --Paolo
>
>
>  On 1/19/12 1:04 AM, Satya Sahoo wrote:
>> Hi Stian,
>> Your example really helps in fleshing out the multiple issues that 
>> are unfortunately being mixed up (in my view), comments are inline:
>>
>>     entity(customerOnRedChair, [prov:location="the red chair in the
>>     cafe"])
>>
>> This is a "class" definition (defining a category of 
>> resources/entities - as used in maths (sets), logic etc.)
>>
>>     entity(paoloInCafe)
>>     entity(stianInCafe)
>>
>> These may be classes (with individuals corresponding to all the times 
>> that paolo or stian are in cafe) or individuals as required by an 
>> application.
>>
>>     entity(paolo)
>>     entity(stian)
>>
>> These are all "individuals" (not a category of resources as 
>> "customerOnRedChair") - these are members of the sets/classes.
>>
>> I believe you mention this distinction between class and instances in 
>> one of your later mails.
>>
>>     specializationOf(paoloInCafe, paolo)
>>     specializationOf(stianInCafe, stian)
>>
>> I think this construct hides many complexities and is incorrect 
>> according well-defined specialization-generalization relationship in 
>> logic, programming languages, maths etc. For example a person is a 
>> not a specialization of the same person in different situations (and 
>> neither are the descriptions/records about that person) :)
>>
>> I agree with James that many of the examples discussed before your 
>> mail were referring to attributes descriptions and not entities.
>>
>> There are two ways of interpreting the above assertions:
>> a) when paoloInCafe is a class (described above) - then the above 
>> construct is incorrect as it is mixing "types" (asserting class to be 
>> specialization of an individual)
>>
>> b) when paoloInCafe is an individual - then again the above construct 
>> is incorrect as specialization is asserted between classes and not 
>> individuals
>>
>>     alternateOf(paoloInCafe, customerOnRedChair)
>>     alternateOf(stianInCafe, customerOnRedChair)
>>
>>
>>     but we probably don't want to then infer:
>>     alternateOf(paoloInCafe, stianInCafe)
>>
>>     and certainly not:
>>     alternateOf(paolo, stian)
>>
>> The above mentioned mixing of types paves the way the following 
>> (seemingly) incorrect inference. I disagree with Paolo that the 
>> incorrect inference is due to absence of time from the above examples.
>>
>> Thanks.
>>
>> Best,
>> Satya
>>
>>     .. neither did overlap the old characterisation intervals, and are
>>     different 'things' in the world.
>>
>>
>>     however, if Paolo and Stian did not sit anywhere else but in the red
>>     chair, we can also have:
>>
>>
>>     specializationOf(paoloInCafe,
>>     customerOnRedChair)specializationOf(stianInCafe, customerOnRedChair)
>>     this implies that for the duration of paoloInCafe, it was also
>>     customerOnRedChair.
>>
>>     --
>>     Stian Soiland-Reyes, myGrid team
>>     School of Computer Science
>>     The University of Manchester
>>
>>
>
>
> -- 
> -----------  ~oo~  --------------
> Paolo Missier -Paolo.Missier@newcastle.ac.uk,pmissier@acm.org
> School of Computing Science, Newcastle University,  UK
> http://www.cs.ncl.ac.uk/people/Paolo.Missier
>    

-- 
Professor Luc Moreau
Electronics and Computer Science   tel:   +44 23 8059 4487
University of Southampton          fax:   +44 23 8059 2865
Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
United Kingdom                     http://www.ecs.soton.ac.uk/~lavm
Received on Thursday, 19 January 2012 09:30:06 UTC

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