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Re: Agenda SPARQL TC 2009-01-05

From: Andy Seaborne <andy.seaborne@talis.com>
Date: Tue, 05 Jan 2010 14:43:59 +0000
Message-ID: <4B43502F.6030301@talis.com>
To: Axel Polleres <axel.polleres@deri.org>
CC: Birte Glimm <birte.glimm@comlab.ox.ac.uk>, SPARQL Working Group <public-rdf-dawg@w3.org>


On 05/01/2010 2:27 PM, Axel Polleres wrote:
> I don't see any problems with that reformulation and it seems to be clearer
> indeed to include that in the definition. Andy? Steve?

I don't think changing solely the definition of Pattern Instance Mapping 
is the best way to do this.

	Andy

>
> We probably won't get there today, but will keep it in mind to bring
> this up separately in the agenda in some of the next TCs.
>
> Axel
>
> On 5 Jan 2010, at 14:14, Birte Glimm wrote:
>
>> The current definition says:
>> A Pattern Instance Mapping, P, is the combination of an RDF instance
>> mapping, σ, and solution mapping, μ. P(x) = μ(σ(x))
>>
>> below the definition there the new sentence:
>> For a BGP 'x', P(x) denotes the result of replacing blank nodes b in x
>> for which σ is defined with σ(b) and all variables v in x for which μ
>> is defined with μ(v).
>>
>> I suggest to put that sentence into the definition and relate it to
>> P(x) = μ(σ(x)). For example:
>> A Pattern Instance Mapping, P, is the combination of an RDF instance
>> mapping, σ, and solution mapping, μ. For a BGP x, P(x) denotes the
>> result of replacing each blank node b in x for which σ is defined with
>> σ(b) and each variable v in x for which μ is defined with μ(v), also
>> denoted as P(x) = μ(σ(x)).
>>
>> Basically, my goal is to make this definition clearer. I think the
>> definition should say what x is since it is not a defined term like
>> RDF-T for example. I also think the definition should say what it
>> means to apply a solution mapping or an RDF instance mapping to a BGP.
>> These are mappings from variables/bnodes to terms. It is never defined
>> what the functions to with BGPs. They don't map BGPs to terms. Here it
>> is assumed that they replace
>> variables/bnodes with the corresponding mappings. That has to be said
>> IMO. It can all be guessed, but it is a definition and it is an
>> important definition. I do not suggest to change anything in the
>> meaning. For me that still counts as errata because the definition
>> just did not mention what it should have mentioned.
>>
>> Anyway, I just wanted the spec to be clear, but if there are
>> objections, I will not spend any more time on this issue.
>>
>> Birte
>>
>> 2010/1/4 Axel Polleres<axel.polleres@deri.org>:
>>> Hi Birte,
>>>
>>>> Query 1.1 uses the Query 1.0 definition and adds a sentence below to
>>>> clarify this, but I would prefer to actually extend the definition
>>>> accordingly if the WG is not opposed to that. IMO, the definition
>>>> leaves a lot for readers to figure out themselves and it is quite an
>>>> essential definition. Such a change would not change the meaning of
>>>> the definition, but extend it so that it is clear what is meant.
>>>
>>> Do you have a concrete proposal for improval to extend the definition?
>>> I'd assume if so, we can discuss it, although probably there is not
>>> enough  time left to agree and include it in this round, so I'd prefer to
>>> postpone this issue to after the next WD round.
>>>
>>> best,
>>> Axel
>>>
>>> On 4 Jan 2010, at 15:00, Birte Glimm wrote:
>>>
>>>> Axel,
>>>> if there is some time in tomorrow's telecon, I would like to discuss
>>>> whether it is possible to clarify the definition of Pattern Instance
>>>> Mapping in Query 1.1.
>>>>
>>>> The Query 1.0 definition says:
>>>> A Pattern Instance Mapping, P, is the combination of an RDF instance
>>>> mapping, σ, and solution mapping, μ. P(x) = μ(σ(x))
>>>>
>>>> The problem is that it is never said what x is and readers have to
>>>> guess that it is a BGP. Even if they guess that x is a BGP, then it is
>>>> still the case that sigma and mu are only defined for blank nodes and
>>>> variables as input, so readers again have to guess that in this case
>>>> it is meant that the blank nodes and variables in the BGP x are
>>>> replaced with the values given by mu and sigma.
>>>>
>>>> Query 1.1 uses the Query 1.0 definition and adds a sentence below to
>>>> clarify this, but I would prefer to actually extend the definition
>>>> accordingly if the WG is not opposed to that. IMO, the definition
>>>> leaves a lot for readers to figure out themselves and it is quite an
>>>> essential definition. Such a change would not change the meaning of
>>>> the definition, but extend it so that it is clear what is meant.
>>>
>>> Do you have a concrete proposal to extend the definition?
>>>
>>>> Birte
>>>>
>>>>
>>>> 2010/1/4 Axel Polleres<axel.polleres@deri.org>:
>>>>> Dear all,
>>>>>
>>>>> first of all, Happy 2010 and looking fwd to welcome you to our first TC this year!
>>>>> On Tuesday, we obviously want to check the status of the reviews and go through them as far
>>>>> as there are any critical comments. We should also check the schedule in case there are reviews
>>>>> missing still, since we want to make a decision to publish (based on reviews&  subsequent
>>>>> updates made by editors) in two weeks at the latest.
>>>>>
>>>>> In case we still have time left with all that on Tuesday (given the speed we rushed through all
>>>>> docs in the last TC before christmas, you never know), I'd like to have a look over the
>>>>> update ISSUEs mentioned in Paul's and Andy's mails [1,2].
>>>>>
>>>>> 1. http://lists.w3.org/Archives/Public/public-rdf-dawg/2009OctDec/0628.html
>>>>> 2. http://lists.w3.org/Archives/Public/public-rdf-dawg/2009OctDec/0674.html),
>>>>>
>>>>> The agenda can be found as usual at: http://www.w3.org/2009/sparql/wiki/Agenda-2010-01-05
>>>>> Will try to complete links to the reviews sent so far before the TC...
>>>>>
>>>>> best,
>>>>> Axel
>>>>>
>>>>> ============================
>>>>> Call in details
>>>>>
>>>>> When joining please don't identify yourself verbally; instead, identify yourself to Zakim on IRC
>>>>>
>>>>>         • Date of Call: Tuesday January 05, 2010
>>>>>         • Time of Call: 15:00 UK, 10:00 (East US)
>>>>>         • Dial-In #: +1.617.761.6200 (Cambridge, MA)
>>>>>         • Dial-In #: +33.4.89.06.34.99 (Nice, France)
>>>>>         • Dial-In #: +44.117.370.6152 (Bristol, UK)
>>>>>         • Participant Access Code: 77277# (SPARQ)
>>>>>         • IRC Channel: irc.w3.org port 6665 channel #sparql ([irc:irc.w3.org:6665/sparql])
>>>>>         • Web-based IRC (member-only): http://www.w3.org/2001/01/cgi-irc (Firefox IRC addon: chatzilla)
>>>>>         • Duration: 60 minutes
>>>>>         • Chair: Axel Polleres
>>>>>         • Scribe: Olivier Corby (Scribe List)
>>>>>         • Link to Agenda: http://www.w3.org/2009/sparql/wiki/Agenda-2010-01-05
>>>>>
>>>>> [edit] Agenda
>>>>>
>>>>>         • Admin
>>>>>                 • PROPOSED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-12-22
>>>>>                 • Next meeting: 2010-01-12 @ 15:00 UK / 10:00 EST (scribe: Alex Passant)
>>>>>         • Comment handling - see http://www.w3.org/2009/sparql/wiki/Comments
>>>>>         • Liaisons - Anything to report?
>>>>>                 • RIF WG (Axel)
>>>>>                 • RDB2RDF WG (Orri)
>>>>>                 • eGov (SteveH)
>>>>>         • Document Reviews and schedule for publication:
>>>>>                 • http://www.w3.org/2009/sparql/docs/query-1.1/
>>>>>                 • http://www.w3.org/2009/sparql/docs/update-1.1/
>>>>>                 • http://www.w3.org/2009/sparql/docs/protocol-1.1/
>>>>>                 • http://www.w3.org/2009/sparql/docs/service-description-1.1/
>>>>>                 • http://www.w3.org/2009/sparql/docs/http-rdf-update/
>>>>>                 • http://www.w3.org/2009/sparql/docs/property-paths/Overview.xml
>>>>>                 • http://www.w3.org/2009/sparql/docs/entailment/xmlspec.xml
>>>>>         • Time allowed: Update ISSUEs, Can we close some? see Paul's and Andy's mails.
>>>>> [edit] Regrets
>>>>>
>>>>>         • Lee Feigenbaum
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Dr. Birte Glimm, Room 306
>>>> Computing Laboratory
>>>> Parks Road
>>>> Oxford
>>>> OX1 3QD
>>>> United Kingdom
>>>> +44 (0)1865 283529
>>>>
>>>
>>>
>>
>>
>>
>> --
>> Dr. Birte Glimm, Room 306
>> Computing Laboratory
>> Parks Road
>> Oxford
>> OX1 3QD
>> United Kingdom
>> +44 (0)1865 283529
>>
>
>
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Received on Tuesday, 5 January 2010 14:44:38 GMT

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