Re: PROV-ISSUE-466 (must-entities-invalidate): Must all entities invalidate? [prov-dm-constraints]

I see no reason to require inferring invalidation and end events.  However, Luc was arguing for this internally.  

Luc's argument (IIRC) is that we know that everything will invalidate or end, and all we are doing here is saying that there must be some such event, and nothing more.  We don't infer a time or any attributes of the events.

However, I think this is orthogonal to validity anyway; an instance that is valid with these inferences will (I think) be valid without, and vice versa, so I don't see a reason to keep if they are controversial.

Luc?

--James


On Aug 6, 2012, at 4:26 PM, Provenance Working Group Issue Tracker wrote:

> PROV-ISSUE-466 (must-entities-invalidate): Must all entities invalidate? [prov-dm-constraints]
> 
> http://www.w3.org/2011/prov/track/issues/466
> 
> Raised by: Stian Soiland-Reyes
> On product: prov-dm-constraints
> 
> Do we have WG consensus on that all entities must be invalidated,
> and all activities must terminate? Seems to talk about the future,
> rather than the past.
> 
>> From Stian's review http://lists.w3.org/Archives/Public/public-prov-wg/2012Aug/0021.html :
> 
> 
>> Inference 7 (entity-generation-invalidation-inference)
> 
>> From an entity, we can infer that existence of generation and invalidation events.
> 
> This REQUIRES entities to become invalidated (at some point). It is
> consistent with entities requiring generation, but it means I get
> inferred strange wasInvalidatedBy for real life entities like:
> 
> entity(math:pi)
> entity(phys:universe)
> entity(phys:vacuum)
> entity(phys:energy)
> entity(concept:existence)
> entity(uk:2011census)
> entity(uspolitics:resultOfPresidentialElection2012)
> 
> When are these destroyed? By what? Is it certain that everything is
> destroyed? What about things that are still existing at the time of
> provenance being written, with this you are requiring them all to die
> - I thought PROV only talked about the past. "We are all going to die"
> - but you don't know when or how - so why should the PROV imply
> provenance statements about the future?
> 
> 
> 
> 


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Received on Monday, 6 August 2012 15:47:56 UTC