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Re: summary so far.

From: Nathan <nathan@webr3.org>
Date: Wed, 02 Mar 2011 19:07:44 +0000
Message-ID: <4D6E9580.804@webr3.org>
To: Jonathan Rees <jar@creativecommons.org>
CC: AWWSW TF <public-awwsw@w3.org>
Jonathan Rees wrote:
> On Wed, Mar 2, 2011 at 1:40 PM, Nathan <nathan@webr3.org> wrote:
>> Pat Hayes wrote:
>>> On Mar 2, 2011, at 11:30 AM, Nathan wrote:
>>>
>>>> Jonathan Rees wrote:
>>>>> You're generting stuff more quickly than I can process it. I will be
>>>>> selective and not comment on everything that I could.
>>>> np, feedback, or a call to discuss, the last iteration:
>>>>  http://lists.w3.org/Archives/Public/public-awwsw/2011Mar/0014.html
>>>> would be appreciated, and how it maps out to, or affects ir-axioms.
>>>>
>>>>> On Wed, Mar 2, 2011 at 5:49 AM, Nathan <nathan@webr3.org> wrote:
>>>>>> Jonathan Rees wrote:
>>>>>> now this is interesting, and I'm unsure exactly how to say it, but if
>>>>>> we
>>>>>> work from HTTP Resource upwards to URI, such that we consider an HTTP
>>>>>> Resource as being a distinct object for which all URIs used to refer to
>>>>>> it
>>>>>> are bound to that HTTP Resource (the URIs are a property of the HTTP
>>>>>> Resource), then we come to the wrong conclusions, and things break.
>>>>> No. Only TimBL's requirement that these be distinct breaks. (Maybe
>>>>> that's what you mean by "things" but you need to be more specific.)
>>>> and RDF's requirement, in fact URIs is it not, that two different URIs
>>>> refer to two different things unless explicitly stated that they refer to
>>>> the same thing?
>>> No. RDF (and RDFS, OWL etc.) make no assumptions about unique naming. Any
>>> two different URIs might or might not refer to the same thing.
>> surely there is some world view, that given <x> and <y>, unless you know,
>> infer, or are told otherwise, then they refer to different things? or is the
>> view that given any two URIs it is default to consider them as all referring
>> to the same thing?
> 
> You have to go back to the model theory to understand this properly.
> The following leaves a few details out, but its sloppiness shouldn't
> detract from the point.
> 
> Suppose you have a graph that contains no logical connectives
> (subclassof etc.). Then it has many (RDF) interpretations, at least
> one in which every URI is interpreted as a distinct individual or
> property, and one in which every URI is interpreted as the same
> individual or property.
> 
> That is, if there are no axioms to tell you, then you just don't know
> what's the same and what's not - the theory of the graph is logically
> incomplete in this regard. The only way an equality or inequality
> would be 'known' is if it were entailed - i.e. true in every
> interpretation.
> 
> Hope that helps.

yes, perfect, ty :)

>> take for example the case in question:
>>  http://lists.w3.org/Archives/Public/public-awwsw/2011Mar/0006.html
>>
>> by looking only at the set of representations only, you'd conclude that they
>> are all the same (?), by looking at the URIs only, you'd conclude that they
>> are different (?)
> 
> To have HTTP feed into an RDF graph you'd have to have specify some
> process doing the translation, with HTTP exchanges as input and RDF
> graphs (axioms) as output. This is sort of implicit in the webarch
> theory but has never been codified really. That process was a chunk of
> the work we did in AWWSW a year or two ago, but it's been put aside
> for now.

ahh yes, I've seen, but not looked in depth so as to understand - 
perhaps I should? (critical for nose-following?)

cheers,

nathan
Received on Wednesday, 2 March 2011 19:08:44 GMT

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