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PROV-ISSUE-136 (collection-functional): Collection not stated as functional [Data Model]

From: Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
Date: Sat, 29 Oct 2011 23:18:24 +0000
To: public-prov-wg@w3.org
Message-Id: <E1RKIAS-0006ye-Qv@barney.w3.org>

PROV-ISSUE-136 (collection-functional): Collection not stated as functional [Data Model]

http://www.w3.org/2011/prov/track/issues/136

Raised by: Stian Soiland-Reyes
On product: Data Model

http://www.w3.org/TR/prov-dm/#expression-Collection introduces relations for expressing collection addition by using three statements

  wasAddedTo_Coll(c2,c1)
  wasAddedTo_Key(c2,k1)
  wasAddedTo_Entity(c2,e1)

Saying that c2 is the content of c1 - but with e1 added under the key k1. 

It is not stated that the relations are functional - thus it would be valid to also say *for the same collection c2*:

  wasAddedTo_Key(c2,k2)
  wasAddedTo_Entity(c2,e2)


But now assuming order of assertions in PROV-ASN don't matter - we don't know if it is (k2,e2) and (k1,e1) that was added, alternatively (k1,e2) and (k2,e1).


My rough interpretation is that these assertions are meant to be functional - so that you can only add one key->entity at a time. If this is true, it should be stated in PROV-DM. 

If it is not - then a different way to associate the key to the value is needed, like a new "CollectionEntry" entity with attributes "key:,  "value" and possibly "collection".
Received on Saturday, 29 October 2011 23:18:26 GMT

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