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Re: PROV-ISSUE-660 (TomDN): Constraints of PROV-Dictionary [PROV-DICTIONARY]

From: Tom De Nies <tom.denies@ugent.be>
Date: Mon, 15 Apr 2013 17:38:33 +0200
Message-ID: <CA+=hbbdmEgC_3rU-CL+035ZtU=E3vxMfPztfckr4_7LP0g7_ag@mail.gmail.com>
To: James Cheney <jcheney@inf.ed.ac.uk>
Cc: Provenance Working Group <public-prov-wg@w3.org>
I've made the revision, as I believe that the inferences D4 and D5 we now
have, imply the old D8 we had, and are much more elegant and clear.
https://dvcs.w3.org/hg/prov/raw-file/default/dictionary/Overview.html#membership-insertion-membership-inference
I've also included a remark explaining this, and which constraints
guarantee completeness.

If there are objections to this change, please let us know before the vote
on Thursday.

ISSUE-660 now marked pending review.

Regards,
Tom

2013/4/15 James Cheney <jcheney@inf.ed.ac.uk>

> I don't think it was discussed.  I don't have an objection, but haven't
> had a chance to think about it very hard.  Either way, I suggest flagging
> this as a point to revisit if there is any future activity on this (e.g.
> formalization).  That is, if you remove a constraint that you think should
> be implied, please mention it in a remark as something that should be
> checked later.  If you leave it in, leave a remark saying that it appears
> redundant (which would mean that implementations can skip it).
>
> --James
>
> On Apr 15, 2013, at 10:49 AM, Tom De Nies <tom.denies@ugent.be> wrote:
>
> I would have liked some feedback on this before we implement it. Any
> thoughts?
> Was anything said about this during last week's telecon?
> Thanks.
> - Tom
>
>
> 2013/4/11 Tom De Nies <tom.denies@ugent.be>
>
>> Small correction, we need to have enough to guarantee that insertions and
>> removals do not introduce *or remove* any key-entity pairs, other than
>> those specified.
>>
>> I think the two proposed constraints are sufficient for this, unless I'm
>> missing something.
>>
>> 2013/4/11 Provenance Working Group Issue Tracker <sysbot+tracker@w3.org>
>>
>>> PROV-ISSUE-660 (TomDN): Constraints of PROV-Dictionary [PROV-DICTIONARY]
>>>
>>> http://www.w3.org/2011/prov/track/issues/660
>>>
>>> Raised by: Tom De Nies
>>> On product: PROV-DICTIONARY
>>>
>>> Luc raised some interesting ideas for the constraints.
>>>
>>> Note that we now have this inference:
>>>
>>> https://dvcs.w3.org/hg/prov/raw-file/default/dictionary/Overview.html#membership-insertion-membership-inference
>>> Inference D4 (membership-insertion-membership) Here, KV1 is a set of
>>> key-entity pairs and K1 is the key-set of KV1.
>>> 1. IF prov:hadDictionaryMember(d1, e, k) and
>>> prov:derivedByInsertionFrom(d2, d1, KV1) and k ∉ K1 THEN
>>> prov:hadDictionaryMember(d2, e, k)
>>> 2. IF prov:hadDictionaryMember(d2, e, k) and
>>> prov:derivedByInsertionFrom(d2, d1, KV1) and k ∉ K1 THEN
>>> prov:hadDictionaryMember(d1, e, k)
>>>
>>> (2nd part suggested by Luc)
>>> I do have one immediate question: do we introduce an infinite loop by
>>> doing this? (consequent of 1. appears in antecedent of 2., and vice versa)
>>> Or is this covered by http://www.w3.org/TR/prov-constraints/#overview ?
>>>
>>> This got me thinking. If we have this, do we really need Inference D8?
>>> https://dvcs.w3.org/hg/prov/raw-file/default/dictionary/Overview.html#insertion-removal-membership-inference
>>>
>>> Couldn't we just specify the same constraint as D4, but for removal?
>>> Suggestion:
>>> Inference D... (membership-removal-membership) Here, K1 is a set of keys.
>>> 1. IF prov:hadDictionaryMember(d1, e, k) and
>>> prov:derivedByRemovalFrom(d2, d1, K1) and k ∉ K1 THEN
>>> prov:hadDictionaryMember(d2, e, k)
>>> 2. IF prov:hadDictionaryMember(d2, e, k) and
>>> prov:derivedByRemovalFrom(d2, d1, K1) THEN prov:hadDictionaryMember(d1, e,
>>> k)
>>> Note that in the second case, k ∉ K1 is always true, otherwise
>>> constraint D9 is violated.
>>>
>>> Do we then have enough to guarantee that insertions and removals do not
>>> introduce any new key-entity pairs, other than those specified? (which is
>>> why we had Inference D8)
>>> I think so, so I'd like to propose this solution. Could we have your
>>> support or objections via mail or on today's call?
>>>
>>> Regards,
>>> Tom
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>
>
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>
>
Received on Monday, 15 April 2013 15:39:02 UTC

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