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Re: prov-dm derivation: three proposals to vote on (deadline Wednesday midnight GMT)

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Tue, 08 Nov 2011 10:33:33 +0000
Message-ID: <EMEW3|063470b741371500bb48c2c067adc85anA7AXa08L.Moreau|ecs.soton.ac.uk|4EB9057D.5000806@ecs.soton.ac.uk>
To: Daniel Garijo <dgarijov@gmail.com>
CC: W3C provenance WG <public-prov-wg@w3.org>
Hi Daniel,
Just realised I missed part of your message.

No, wasDerivedFrom(e2,e1) implies dependedUpon(e2,e1). Not the converse,
since dependedUpon makes no assumption about activities, whereas 
wasDerivedFrom does.

So, in your example, you can indeed infer dependedUpon(e2,e0), but it 
does not mean
that wasDerivedFrom(e2,e0).

I hope it clarifies this issue. In fact, from that point of view, 
nothing has changed compared to the
current document.
Cheers,
Luc


On 11/08/2011 10:24 AM, Daniel Garijo wrote:
> +1 For proposal 1, *?* for proposal 2 and +1 for proposal 3.
>
> I'm a bit confused by proposal 2. I don't see what is special in that 
> type of derivation
> that currently doesn't exist in the model. Could you please give more 
> details, please?
>
> Also, I thought that the inference was that if dependedUpon(e2,e1) 
> holds, then implies wasDerivedFrom(e2,e1).
>
> According to what is proposed, if we have wasDerivedFrom(e2,e1), 
> wasDerivedFrom(e1,e0) (but e2 not being
> derived from e0, because it is not transitive), it would imply: 
> dependedUpon(e2,e1), dependedUpon(e1,e0). Since
> dependedUpon is transitive, we would also inferr dependedUpon(e2,e0), 
> and that would be wrong.
>
> Thanks,
> Daniel
>
> 2011/11/7 Luc Moreau <l.moreau@ecs.soton.ac.uk 
> <mailto:l.moreau@ecs.soton.ac.uk>>
>
>     Dear all,
>
>     Can you express your support or not for the following proposals.
>     We will confirm
>     the outcome at the teleconference.
>
>     Best regards,
>     Luc
>
>
>     In the interest of simplification, we would like to make the following
>     proposal about derivations in prov-dm.
>
>     Context: prov-dm currently contains 3 different notions of
>     derivations, in particular with names that are not intuitive.  The
>     constraint derivation-attributes [1] prevented derivations to be
>     transitive. These constraints were removed from the prov-dm document
>     last week [2].
>
>
>
>     Proposal 1. Transitive derivation is expressed using 'dependedUpon'
>                between two entities.  dependedUpon can be asserted or
>     inferred.
>
>     Proposal 2.  There exists a special case of derivation, where a
>                 process execution is known or known to exist.  This is
>     expressed using:
>                 wasDerivedFrom(e2,e1,[pe, ...])  and its compact form
>                 wasDerivedFrom(e2,e1).
>
>                 Furthermore, there exists an inference:
>                 wasDerivedFrom(e2,e1,[pe, ...]) implies
>     dependedUpon(e2,e1).
>
>     Proposal 3.  In the current version of the document,
>     wasEventuallyDerivedFrom and dependedOn intended to
>                  express the same notion of (transitive) derivation,
>     and thus can be
>                  removed as redundant.
>
>
>
>     Instead of 3 relations wasDerivedFrom, wasEventuallyDerivedFrom, and
>     dependedOn, we would now only have 2 relations wasDerivedFrom and
>     dependedUpon. The awkward term 'wasEventuallyDerivedFrom' is also
>     abandonned.  Overall, this should contribute towards a simplification
>     of the model.
>
>
>     Note: the text will describe the conditions under which the binary
>     form of wasDerivedFrom is transitive.
>
>
>
>
>     [1]
>     http://www.w3.org/TR/2011/WD-prov-dm-20111018/#derivation-attributes
>     [2] http://www.w3.org/2011/prov/meeting/2011-11-03#resolution_5
>
>
>

-- 
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 Tuesday, 8 November 2011 10:34:15 UTC

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