Re: PROV-ISSUE-29 (mutual-iVP-of): can two bobs be mutually "IVP of" each other [Conceptual Model]

Your example is correct...but I the common thing were talking about is the thing in the chair,

But maybe the gurus should step in
Paul

On Apr 1, 2012, at 21:20, Luc Moreau <L.Moreau@ecs.soton.ac.uk> wrote:

> 
> 
> 
> On 1 Apr 2012, at 12:12, "Paul Groth" <p.t.groth@vu.nl> wrote:
> 
>> My answers:
>> 
>> 1. An entity refers to one thing that thing may or may not be identified
> 
> 
> At a given point in time, possibly, but is it the case when time changes?
> 
> Can't recall the exact detail, but the 'customer on the third chair' may be the
> woman in red at t1 and the man in black at t2. Can't it?
> 
> 
> Luc
> 
> 
>> 
>> 2. Specialization thus is defined in terms of 1
>> 
>> Paul - not a specialization/alternator guru 
>> 
>> On Apr 1, 2012, at 9:46, Luc Moreau <l.moreau@ecs.soton.ac.uk> wrote:
>> 
>>> Hi all specializationOf/alternateOf gurus,
>>> 
>>> The current definition of alternateOf does not allow us to decide whether James's or my interpretation
>>> is right.  The question is essentially: does an entity refer to one and only one thing or not.
>>> 
>>> So, 
>>> 
>>> 1. What is intended?
>>> 2. How do we clarify definitions?
>>> 
>>> Cheers,
>>> Luc
>>> 
>>> 
>>> On 31/03/2012 15:46, James Cheney wrote:
>>>> 
>>>> On 30/03/12 10:01, Luc Moreau wrote:
>>>>> 
>>>>> 
>>>>> Dear all,
>>>>> 
>>>>> I am getting conflicting messages on this topic!
>>>>> 
>>>>> James has listed some properties derived from the semantics
>>>>> http://lists.w3.org/Archives/Public/public-prov-wg/2012Mar/0470.html
>>>>> But not all of them seem to be aligned with what we are reading on this thread.
>>>>> 
>>>>> So, I started drafting a section in prov-dm part II listing the properties of these relations [1].
>>>>> 
>>>>> I am proposing to justify each property either by reasoning based on its definition,
>>>>> or by a counter-example.
>>>>> 
>>>>> Your suggestions are needed to help us complete this section.  
>>>>> 
>>>>> James, unless my reasoning is incorrect, I do not have transitivity for specializationOf.
>>>> 
>>>> Hi Luc,
>>>> 
>>>> Your reasoning (quoting from [1])  is:
>>>> 
>>>>> Specialization is not transitive. Indeed if specializationOf(e1,e2) holds, then there is some common thing, say e1-2 they both refer to. Likewise, if specializationOf(e2,e3) holds, then there is some common thing, say e2-3 they both refer to. It does not follow there is a common thing both e1 and e3 refer to.
>>>> 
>>>> In the WD3 formal semantics [2], I modeled entities-referring-to-things as a function thingOf : Entity -> Thing.  
>>>> 
>>>> Thus, if thingOf(e1) = e1-2 = thingOf(e2) and thingOf(e2) = e2-3 = thingOf(e3) then (by transitivity of equality) e1-2 = e2-3 and all three entities refer to the same thing, e1-2.
>>>> 
>>>> Of course, it is an assumption I made that an entity "refers to" exactly one thing.  If we want to allow entities to refer to multiple things, then the reasoning I give above fails, and specializationOf is not necessarily transitive.
>>>> 
>>>> --James
>>>> 
>>>> [1] http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-dm-constraints.html#component4
>>>> [2] http://www.w3.org/2011/prov/wiki/FormalSemanticsWD3
>>>> 
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>>>> Scotland, with registration number SC005336.
>>>>