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Re: life without dataset semantics

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Wed, 19 Sep 2012 09:48:01 -0400
Message-ID: <5059CD11.10505@gmail.com>
To: Sandro Hawke <sandro@w3.org>
CC: David Wood <david@3roundstones.com>, "public-rdf-wg@w3.org Group WG" <public-rdf-wg@w3.org>
I'm not convinced that there is any need to restrict properties like 
sendCorrectionsTo to datasets.

peter

On 09/19/2012 09:40 AM, Sandro Hawke wrote:
> On 09/19/2012 09:13 AM, Peter F. Patel-Schneider wrote:
>> What do you think that the minimal semantics will get you?
>>
>
> I'm kind of in the crossfire here.   I'm not arguing for the minimal 
> semantics.   I'm happy with no semantics/any semantics, as long as I can do 
> my sendCorrectionsTo example (quoted below).   In my implementation work in 
> the spring I came to the conclusion that all I need to implement all the 
> GRAPHS use cases that I understood was the ability to define predicates like 
> that.
>
>> So far, I've heard only one thing.  If g1 and g2 denote the same thing, 
>> then their graphs, if any, are put together (in essence). However, you 
>> can't do much of that kind of inference in RDF, so I don't think that there 
>> is much gain here.
>>
>> In the example below, it seems to me that you can proceed exactly the same 
>> with the minimal dataset semantics, with no semantics at all, and with the 
>> entailment-only semantics.
>>
>
> You're probably right.    There are just semantic bits in defining 
> sendCorrectionsTo that I'm kind of confused about, like whether it makes 
> sense to define an RDF property that only has meaning when it's used in a 
> dataset.   That's a little weird; maybe there's a better way to define it?
>
>        -- Sandro
>
>> peter
>>
>>
>> On 09/18/2012 07:22 PM, Sandro Hawke wrote:
>>> So, elsewhere you're proposing we not have dataset semantics.   I think 
>>> I'm okay with that, if I can still do what I'm trying to do here.      
>>> What I'm not entirely clear on is how I can do this without any semantics....
>>>
>>> On 09/18/2012 02:10 PM, Peter F. Patel-Schneider wrote:
>>>>>
>>>>> Here's a much better example, because it stays away from Web stuff:
>>>>>
>>>>>     <g1> eg:sendCorrectionsTo <mailto:sandro@w3.org>.
>>>>>     <g1> { w3c:group35462 rdfs:label "SPARQL Working Group" }.
>>>>>     <g2> eg:sendCorrectionsTo <mailto:ivan@w3.org>.
>>>>>     <g2> { w3c:group44350 rdfs:label "RDFa Working Group" }.
>>>>>
>>>>>
>>>>> There's an obvious meaning to the predicate eg:sendCorrectionsTo, but 
>>>>> how do I express that meaning? Something like:
>>>>>
>>>>>     X eg:sendCorrectionsTo Y
>>>>>
>>>>>         Note: only meaningful inside a dataset which has a named graph with
>>>>>         the name X.
>>>>>
>>>>>         Meaning: Y is a good email address for sending corrections to the
>>>>>         information in the named graph X.
>>>>>
>>>>> Are you comfortable with that?
>>>>
>>>> I don't know if comfortable is the right word.  I don't have problems 
>>>> with anyone wanting to do that.
>>>
>>> My question is really: do you think that definition/documentation means 
>>> what I want it to and will work the way I want it to, if the RDF WG 
>>> doesn't give Datasets any semantics?
>>>
>>> That is, if the WG doesn't say anything about graph-name URIs connecting 
>>> to URIs as used in the default graph, can I just spell all that out (as 
>>> above) in the documentation of my predicate?
>>>
>>> And if I can't, then what alternative do I have for sharing this kind of 
>>> information structure?
>>>
>>>>   I can see that if this is the stance that someone wants to take with 
>>>> respect to named graphs, then one might want to have the relationship 
>>>> between IRIs and graphs work the way it works in the minimal semantics.
>>>>
>>>> However,  I don't think that everyone wants to have this connection.
>>>
>>> What I'm asking for is an extremely weak connection; it's hard for me to 
>>> see how it would do any harm, since it would only come into play when 
>>> someone ask for it.
>>>
>>>       -- Sandro
>>>
>>
>>
>
Received on Wednesday, 19 September 2012 13:48:34 GMT

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