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Re: Determination of subjects/objects

From: Ivan Herman <ivan@w3.org>
Date: Fri, 27 Jul 2007 18:39:06 +0200
Message-ID: <46AA1FAA.6070401@w3.org>
To: Mark Birbeck <mark.birbeck@formsPlayer.com>
CC: Ben Adida <ben@adida.net>, public-rdf-in-xhtml-tf@w3.org
Mark, why are you telling that to me? I did not invent this term...

I.

Mark Birbeck wrote:
> Hi Ivan,
> 
> Sure...it's just that in RDF there isn't really a notion of naming a
> statement. (Not one that comes without getting into a pickle.) And
> also, giving an 'RDF identity' to an HTML element is something we
> should debate and agree on before we start using it widely, since it's
> also not without its problems.
> 
> So I'd suggest we leave that term to one side.
> 
> Regards,
> 
> Mark
> 
> On 27/07/07, Ivan Herman <ivan@w3.org> wrote:
>> Any term is fine with me at that point...
>>
>> Ivan
>>
>> Mark Birbeck wrote:
>>> Ivan,
>>>
>>> I'm not sure that the 'RDF identity' is a useful term. I can see why
>>> Ben introduced it, to help formulate the rules summary, but I'm not
>>> sure it does actually help.
>>>
>>> Another way to look at what is being done is that the 'context' for
>>> contained statements is being set; we could say that the context is
>>> set by the value of @href, or @resource, or some bnode, or whatever.
>>>
>>> Regards,
>>>
>>> Mark
>>>
>>> On 27/07/07, Ivan Herman <ivan@w3.org> wrote:
>>>> Ben Adida wrote:
>>>>>> [ a rdf:Seq;
>>>>>>      rdf:_1 <#A>;
>>>>>>      rdf:_2 <#B>.
>>>>>> ]
>>>>>> <#A> p:q "bla2".
>>>>>> <#B> p:q "bla2".
>>>>>>
>>>>>> Note that, as a side effect of the Ben rules, there is _no_ difference
>>>>>> between @about and @href in this setting...
>>>>> Okay, *this* is a problem, I think. I know the way I worded "the rules",
>>>>> it appears that @about is then the RDF identity, so it appears that it
>>>>> can be the object when you write:
>>>>>
>>>>>    <li rel="rdf:_1" about="#A">
>>>>>
>>>>> but I think that is very wrong. Because, if you add @resource, then
>>>>> @about suddenly becomes the subject. And that's quite confusing.
>>>>>
>>>>> It leads me to wonder if the rules are a bit wrong or inconsistent.
>>>>>
>>>>> If you were to write resource="#A", then I would agree, but as it
>>>>> stands, it bothers me. And, in fact, this is the Achille's heel of this
>>>>>  "syntactic sugar for collections" issue: if you add other RDFa
>>>>> attributes, you screw up the resulting output.
>>>>>
>>>> Ben, I remember I was surprised when realizing that, too. But, just to
>>>> really separate the issues, I do not believe this has anything to do
>>>> with the collection issue. The very same happens with
>>>>
>>>> <span rel="a:b" about="#b">asasfas</span>
>>>>
>>>> You rules in
>>>>
>>>> http://www.w3.org/mid/46A8D3ED.2080404@adida.net
>>>>
>>>> say:
>>>>
>>>> - - @rel (conversely @rev) creates triples with the given predicate. The
>>>> object of @rel (conversely the subject of @rev) is the "RDF identity" of
>>>> the current element...
>>>>
>>>> - the RDF identity of an HTML element is, in order of precedence
>>>>         - @resource
>>>>         - @href
>>>>         - @src if it's an IMG
>>>>         - @about
>>>>         - a new bnode
>>>>
>>>> meaning that we would get
>>>>
>>>> <> a:b #b.
>>>>
>>>> for the element above and if we added a @href then suddenly the @about
>>>> becomes the subject of a:b.
>>>>
>>>> I am not saying this is not confusing, I am just saying that this is
>>>> _not_ related to the collection syntactic sugar. Ie, I still believe the
>>>> collection issue is, essentially, closed (I can use @resource in all my
>>>> examples, eg, as resource="_:", without problems).
>>>>
>>>> I am not sure what to do with that stuff. I have to run now, maybe you
>>>> may want to look at the different cases with the @about removed from the
>>>> RDFI calculation.
>>>>
>>>>
>>>>
>>>> [snip]
>>>>> I have a visceral problem with about="_:", and that is that it makes
>>>>> bnodes explicit, which I really don't want to do to HTML authors. That's
>>>>> just too much RDF.
>>>>>
>>>>> We may begin to hit diminishing ROI here, and I'm starting to lean
>>>>> towards supporting fewer of these constructs in order to not complicate
>>>>> the syntax. I can't see myself being convinced that about="_:" is going
>>>>> to help without hurting more....
>>>>>
>>>> I do believe that (1) "_:" will be very rarely used and for RDF people
>>>> only but (2) in some edge cases it is difficult to avoid it. Any other
>>>> syntactic solution would lead to real complications I believe, and I
>>>> also believe that getting a sequence of anonymous and untyped bnodes is
>>>> sometimes necessary...
>>>>
>>>> Ivan
>>>>
>>>>
>>>>
>>>>> -Ben
>>>>>
>>>> --
>>>>
>>>> Ivan Herman, W3C Semantic Web Activity Lead
>>>> Home: http://www.w3.org/People/Ivan/
>>>> PGP Key: http://www.ivan-herman.net/pgpkey.html
>>>> FOAF: http://www.ivan-herman.net/foaf.rdf
>>>>
>>>>
>>>
>> --
>>
>> Ivan Herman, W3C Semantic Web Activity Lead
>> Home: http://www.w3.org/People/Ivan/
>> PGP Key: http://www.ivan-herman.net/pgpkey.html
>> FOAF: http://www.ivan-herman.net/foaf.rdf
>>
>>
> 
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf


Received on Friday, 27 July 2007 16:39:17 GMT

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