- From: Timothy Lebo <lebot@rpi.edu>
- Date: Mon, 2 Apr 2012 08:40:31 -0400
- To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Cc: James Cheney <jcheney@inf.ed.ac.uk>, Paul Groth <p.t.groth@vu.nl>, "public-prov-wg@w3.org" <public-prov-wg@w3.org>
- Message-Id: <04089ED8-CE83-4386-97DE-EBC6A22B2B5D@rpi.edu>
On Apr 2, 2012, at 5:27 AM, Luc Moreau wrote: > Hi James, > > > >> >> I see absolutely no point to or motivation for allowing an entity to refer to more than (or less than) one thing. >> > So, still trying to understand, if it's the case, what is the point of talking about things? > Shouldn't the English definition of these concepts be expressed without the term 'thing'? +1 -Tim > > Luc > > >> --James >> >> On Apr 1, 2012, at 8:20 PM, Luc Moreau 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 >>>>>> >>>>>> The University of Edinburgh is a charitable body, registered in >>>>>> Scotland, with registration number SC005336. >>>>>> >> >> >> The University of Edinburgh is a charitable body, registered in >> Scotland, with registration number SC005336. >> > > -- > 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 Monday, 2 April 2012 12:41:19 UTC