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Re: PROV-ISSUE-197: Section 5.4.1 and Section 5.4.2 (PROV-DM as on Dec 5)

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Thu, 08 Dec 2011 10:33:50 +0000
Message-ID: <EMEW3|1a5c2b4b726b533c2fde34f083fb6a14nB7AXr08L.Moreau|ecs.soton.ac.uk|4EE0928E.7050406@ecs.soton.ac.uk>
To: public-prov-wg@w3.org
Hi Satya,

On 12/07/2011 02:17 AM, Provenance Working Group Issue Tracker wrote:
> PROV-ISSUE-197: Section 5.4.1 and Section 5.4.2 (PROV-DM as on Dec 5)
> http://www.w3.org/2011/prov/track/issues/197
> Raised by: Satya Sahoo
> On product:
> Hi,
> The following are my comments for Section Section 5.4.1 and Section 5.4.2 of the PROV-DM (as on Dec 05):
> Section 5.4.1:
> 1. "Given an entity record identifier e, two sets of attribute-values denoted by av1 and av2, two entity records entity(e,av1) and entity(e,av2) occurring in an account are equivalent to the entity record entity(e,av) where av is the set of attribute-value pairs formed by the union of av1 and av2."
> Comment: Since entity record identifier and entity identifier are stated to be the same in DM (Section 5.2.1), this constraint should be applicable to entities also.
So, the constraint implies that we have a record

entity(e,av1 u av2)

in the current account.
This record is a representation of the entity e with all attributes av1 
u av2 describing the situation of e.
> In that case, this constraint should hold across accounts also?

No, why should it?

> 2. "Application of identified-entity-in-account results in an entity record containing the attribute-value pairs age=20 and age=30. This results in an inconsistent characterization of a person."
> Comment: This is incorrect. The above characterization may be valid at different points in time or events (when the Berlin Wall fell, East and West Germany unified) etc. I don't think this example is needed in DM.

I think you took the sentence out of context. It is followed by: "We 
note that deciding whether a set of attribute-values is consistent or 
not is application specific and outside the scope of this 
specification.". This addresses your concern.
> 3. "Account records constitute a scope for record identifiers. Since accounts can be nested, scopes can also be nested; thus, the scope of record identifiers should be understood in the context of such nested scopes. When a record with an identifier occurs directly within an account, then its identifier denotes this record in the scope of this account, except in sub-accounts where records with the same identifier occur."
> Comment: This issue has been previously raised multiple number of times. The current version of the DM considers identifiers for entity and entity records to be same - hence the above applies to entity identifiers, which violates the Web architecture for globally unique identifiers and strictly monotonic notion of RDF semantics.
This should be discussed under PROV-ISSUE-183.

> --------------
> Section 5.4.2
> 1. Given the account construct that already has all the functionalities of a record container (with additional information about asserter), why is a separate construct of "record container" needed?
Where do you declare your namespaces?
Isn't there a root somewhere?
The container plays both roles.


> Thanks.
> Best,
> Satya

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 Thursday, 8 December 2011 10:34:22 UTC

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