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Re: TDL conflicts with the "duh!" requirement

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Mon, 28 Jan 2002 16:33:55 +0200
To: Dan Connolly <connolly@w3.org>
CC: RDF Core <w3c-rdfcore-wg@w3.org>
Message-ID: <B87B2DF3.C777%patrick.stickler@nokia.com>
On 2002-01-28 15:29, "ext Dan Connolly" <connolly@w3.org> wrote:

> On Mon, 2002-01-28 at 04:57, Patrick Stickler wrote:

>>> In the TDL proposal, I cannot do this,
>>> because I am not licensed to infer
>>> that the "red" in the first line and
>>> the "red" in the head
>>> of the rule denote the same thing
>>> in all interpretations.
>> 
>> And you say that S does license such an
>> inference?
> 
> Yes.

I don't see how that is possible. S might say that
literal nodes are tidy, such that a given literal
resides at one and only one node, but I don't think it
says that a given literal has the same interpretation
(maps to the same value in the value space of a
single datatype) in all contexts, always.


>> But that's not the same as saying they are all
>> strings (or xsd:string) as once you introduce
>> any local typing for a literal,
> 
> I don't introduce "local typing for a literal".
> 
> I'm not sure what you mean by "local typing"
> (is that covered in the desiderata somewhere?
> Did I neglect to do some reading?)

See items 5 and 7 of the desiderada.

See sections 3.1 and 3.3 of the TDL proposal.

See section 4.9, Idiom A of the S proposal.

All have to do with local (vs. global) typing.


> It's true that S-A works better locally, and S-B works
> better globally, and you have to choose one or support
> both or whatever. This is an issue with S. But I find
> it acceptable.

Nope. Sorry. You can't use both. They are not compatible
in the same knowledge base.

What happens when you choose to use S-B and I choose to
use S-A and then we want to syndicate our knowledge
but can't because our idioms are not compatible?

I consider this to be a major show stopper for S.
 
>> It is no different than
>> 
>>  :Bilbo :age "111".
>>  
>>  { ?x :age "111" }
>>  log:implies { ?x a :EleventyOner }.
>> 
>> Yet, your implication is based on the implicit
>> presumption that values are in decimal notation.
> 
> No, it's based on a design choice that whatever "111"
> denotes, it denotes that same thing in all interpretations.

Hmmm.... Is this an application design choice?

How will my application know about your application's
typing expectations when I get your data?
 

>> If you really want to capture the implication,
>> you must also specify the datatype which ensures
>> the expected interpretation of the lexical form.
> 
> Nope. All I need to say is that "111" denotes
> the same thing in all interpretation and
> the inference follows.

Well, you're going to have a very tough
time freely exchanging knowledge with others
when your expectations about what
are (to RDF) local names are not shared
globally by others.
 


> Yes, the scalar datatype.

So RDF datatypes can only be integers or strings?

>> Merging of literal labeled nodes in S does not assert the
>> same resource equality as merging of URI labeled nodes,
> 
> yes, it does.

Sergey? Can you confirm that?
   
Patrick

--
               
Patrick Stickler              Phone: +358 50 483 9453
Senior Research Scientist     Fax:   +358 7180 35409
Nokia Research Center         Email: patrick.stickler@nokia.com
Received on Monday, 28 January 2002 09:32:56 EST

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