Re: PROV-ISSUE-458: wasInfluencedBy is not irreflexive [prov-dm-constraints]

I added the irreflexivity constraint directly to address concerns raised in discussion by Tim and Tom on issue 454.  I haven't heard whether this proposed fix, or Luc's example of a reflexive communication, addresses their concern.

Briefly, I think wasInformedBy(a,a) is a bug, and we should fix it by dropping generation-use-communication, and keeping influence irreflexive.  However, I'm not going to fight for irreflexive influence if Luc's example convinces everyone else that it may be reflexive.

I am copying my comments from issue 454 for easy reference:
> The irreflexivity constraint was an attempt to address Tim and Tom's concerns, so they should comment on whether your example persuades them that it is not irreflexive.
> 
> My inclination would be that influence and communication should be irreflexive, so this is no problem.  
> 
> But if we also allow the generation-use-communication inference, then from the totally reasonable:
> 
> wasGeneratedBy(e,a)
> used(a,e)
> 
> we could infer wasInformedBy(a,a) and then wasInfluencedBy(a,a), which would be invalid if influence has to be irreflexive.
> 
> Overall, I think this makes a persuasive argument for dropping generation-use-communication and keeping irreflexivity of influence (and all this entails).

--James

On Jul 20, 2012, at 9:07 AM, Provenance Working Group Issue Tracker wrote:

> PROV-ISSUE-458: wasInfluencedBy is not irreflexive  [prov-dm-constraints]
> 
> http://www.w3.org/2011/prov/track/issues/458
> 
> Raised by: Luc Moreau
> On product: prov-dm-constraints
> 
> Going back to the definition in prov-dm,
> 
> Communication is the exchange of some unspecified entity by two activities, one activity using some entity generated by the other.
> 
> I can imagine a service invoking itself (so effectively, exchanging an entity with itself).
> 
> So, it would  be fine to write:
> 
> wasInformedBy(a,a)   
> 
> Therefore, 
> 
> wasInfluencedBy(a,a)
> 
> which contradicts the constraints:
> 
> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#impossible-influence-reflexive
> 
> 
> 
> 
> 
> 
> 


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Received on Friday, 20 July 2012 10:56:13 UTC