- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Thu, 19 Apr 2012 04:35:47 +0000
- To: James Cheney <jcheney@inf.ed.ac.uk>
- CC: Provenance Working Group <public-prov-wg@w3.org>, Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
Hi James, I don't think your description of the problem is accurate. The production [1] is not ambiguous (LL grammar), it definitely does not require multiple pass over the document to recognise types. I think the confusion may have come from the description of the grammar but Paolo has reworked it. As far as the reading of - is concerned, I would even say that we have the following cases: - value exists and is known but not expressed (say, because not deemed important) - value existence is known but actual value is unknown - value does not exist - value existence is not known So, your suggested split absent/unknown may not be the clearest. I believe your Proposal 0 is implemented in the grammar. I considered variants of Proposal 1 but ruled them out because the grammar was not ambiguous. [1] http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-n.html#Derivation-Relation Professor Luc Moreau Electronics and Computer Science University of Southampton Southampton SO17 1BJ United Kingdom On 19 Apr 2012, at 00:33, "James Cheney" <jcheney@inf.ed.ac.uk> wrote: > OK, I've posted my thoughts on this, and a proposal, at: > > http://www.w3.org/2011/prov/wiki/Optional_arguments > > (Sorry this is a bit long, but I think it is worth being a little pedantic here). > > I'd like to keep this open for discussion, but don't think it's a blocking issue. > > --James > > On Apr 18, 2012, at 10:43 AM, James Cheney wrote: > >> Hi, >> >> I have been working on the optional arguments in part 2, and I am still not sure what to write baed on what is in part 1 now. I am trying to formulate a proposal to see if I am on the right track. So I think this should be kept open for now (maybe it should be reassigned to prov-dm-constraints). >> >> --James >> >> >> On Apr 18, 2012, at 7:51 AM, Luc Moreau wrote: >> >>> Hi Stian, >>> Can we close this issue now? >>> Regards, >>> Luc >>> >>> On 04/02/2012 03:58 PM, Luc Moreau wrote: >>>> Hi Stian, >>>> >>>> If you follow [1] below, you will now find our proposed answer to optional arguments. >>>> It contains explicit links to prov-dm part 2. >>>> >>>> I propose to close this issue pending your review. >>>> Regards, >>>> Luc >>>> >>>> >>>> On 03/30/2012 04:12 PM, Luc Moreau wrote: >>>>> >>>>> Hi Stian, >>>>> >>>>> I have been thinking about your suggestion on optional arguments. >>>>> I looked at all the optional arguments [1] in prov-dm. >>>>> >>>>> Most of them, I believe, imply existential quantification. >>>>> >>>>> It would be nice to have this confirmed, and then we can write it up in part 2. >>>>> >>>>> Luc >>>>> >>>>> [1] http://dvcs.w3.org/hg/prov/raw-file/default/model/optional.html >>>>> >>>>> On 13/03/2012 11:05, Provenance Working Group Issue Tracker wrote: >>>>>> PROV-ISSUE-311 (clarify-optionals): Clarify optional arguments in DM [prov-dm] >>>>>> >>>>>> http://www.w3.org/2011/prov/track/issues/311 >>>>>> >>>>>> Raised by: Stian Soiland-Reyes >>>>>> On product: prov-dm >>>>>> >>>>>> There seems to be some confusion over any of the 'optional' arguments in >>>>>> PROV-DM/PROV-N. >>>>>> >>>>>> It is unclear if this means that the argument is *implied* (ie. >>>>>> existential quantification/bnodes in OWL/RDF) or not applicable/not present (NIL). >>>>>> >>>>>> It might be good to go through all of the optionals in PROV-DM and make sure they make that clear. >>>>>> >>>>>> For instance: >>>>>>> Generation, written wasGeneratedBy(id,e,a,t,attrs) in PROV-N, has the following components: >>>>>>> id: an optional identifier for a generation; >>>>>>> entity: an identifier for a created entity; >>>>>>> activity: an optional identifier for the activity that creates the entity; >>>>>>> time: an optional "generation time", the time at which the entity was completely created; >>>>>>> attributes: an optional set of attribute-value pairs that describes the modalities of generation of this entity by this activity. >>>>>> Change to: >>>>>> >>>>>> >>>>>>> Generation, written wasGeneratedBy(id,e,a,t,attrs) in PROV-N, has the following components: >>>>>>> id: an optional identifier for a generation, if unspecified the identifier is not known; >>>>>>> entity: an identifier for a created entity; >>>>>>> activity: an optional identifier for the activity that creates the entity, if unspecified activity is still implied, but unknown; >>>>>>> time: an optional "generation time", the time at which the entity was completely created, if unspecified the time is unknown or not applicable; >>>>>>> attributes: an optional set of attribute-value pairs that describes the modalities of generation of this entity by this activity, if unspecified an empty set is implied. >>>>>> >>>>>> >>>>>> >>>>> >>>> >>> >>> -- >>> 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 >>> >>> >>> >> >> >> -- >> The University of Edinburgh is a charitable body, registered in >> Scotland, with registration number SC005336. >> >> >> > > > -- > The University of Edinburgh is a charitable body, registered in > Scotland, with registration number SC005336. >
Received on Thursday, 19 April 2012 04:37:01 UTC