Re: Regarding the definition of IVP OF

Hi Khalid

On page [1], we replaced "if" by "only if".  So the condition is 
necessary, and not sufficient.
In other words, "IVP of" must be asserted, and cannot be inferred. I 
think it has always
been the intent.

Luc

[1] http://www.w3.org/2011/prov/wiki/F2F1ConceptDefinitions

On 07/08/2011 04:01 PM, Khalid Belhajjame wrote:
>
> During the F2F meeting, there was a discussion in the second day 
> regarding "IVP of". The definition that was suggested during the F2F 
> can be found in [1]. In my opinion, the definition of "IVP of" should 
> be simplified. Specifically, I would prefer a definition that states 
> that "IVP of" is an asserted relationship between two entity states. I 
> list in what follows the reasons:
>
> (i) In the definition of "IVP of" [1], the conditions on the 
> properties of the two entity states A and B (i.e., that the properties 
> the entity states share must have corresponding values, and that some 
> mutable properties of A correspond to some immutable properties of B), 
> are not enough in order to infer that B is an IVP of A. This is 
> because there is a third condition that is not included, because it is 
> hard to formally specify, viz. A and B are consistent.
>
> (ii) A consequence of (i), is that we will not be able to 
> automatically infer that an entity state B is an IVP of another entity 
> state B. All we can safely do, is identify cases in which an entity 
> state B cannot be an IVP of another entity state of A.
>
> (iii) Even if we find a means for formally specifying that two entity 
> states A and B are consistent, e.g., using assertions, it will be 
> difficult to use the definition of IVP of to make inference. This is 
> because the definition of IVP of requires correspondences between the 
> properties of two entity states to be specified. These correspondences 
> can be complex many-to-many mappings that may turn out to be hard to 
> encode using existing semantic web technologies.
>
> Thanks, khalid
>

-- 
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
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