W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > November 2001

RE: Literals: lexical spaces and value spaces

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Wed, 7 Nov 2001 16:40:57 -0600
Message-Id: <p05101066b80f665de358@[65.212.118.166]>
To: bwm@hplb.hpl.hp.com, Patrick.Stickler@nokia.com
Cc: w3c-rdfcore-wg@w3.org
>  > -----Original Message-----
>  > From: ext Brian McBride [mailto:bwm@hplb.hpl.hp.com]
>>  Sent: 07 November, 2001 19:42
>>  To: Stickler Patrick (NRC/Tampere)
>>  Cc: phayes@ai.uwf.edu; w3c-rdfcore-wg@w3.org
>>  Subject: Re: Literals: lexical spaces and value spaces
>>
>>
>>
>>
>>  Patrick.Stickler@nokia.com wrote:
>>
>>  [...]
>>
>>
>>  >
>>  > The reason why a range definition cannot be descriptive
>>  > of non-locally typed literals, is because lexical form
>>  > is specific to a given data type, and the binding of
>>  > a value to a given property may occur by various means
>>  > and one can end up with a literal value having a lexical
>>  > form that is not compatible with the data type of the
>>  > property.
>>
>>
>>  Please can we have at least one concrete example, analysed
>>  for each of the three
>>  proposals S, P, X.
>>
>>  Brian
>
>Perhaps I'm not understanding the S and P proposals, but
>I don't see how any examples can be created that are
>relevant to any of the proposals, as the S P and X
>proposals are about attaching type to literals, right?
>
>What I'm talking about is when there is *no* type attached
>locally to the literal. It's just the literal.

OK, let me try to offer an example.

aaa eg:prop "10" .

That's all. That is legal in P, but it is ambiguous until more 
information is given enabling the literal node to be assigned a 
datatype. (Eg by specifying the range of eg:prop to be a datatype 
class.)

This is syntactically illegal in X, since one would have to use a URV 
rather than the bare literal.

I am not sure what the S form would be; as far as I can see, there 
would be no way to say this in S, since the only place for the 
literal to go would be at the sharp end of an edge labelled with a 
datatype, which by hypothesis we don't have at this time. (Sergey, 
can you comment?)

So it seems to me that both X and S, in different ways, simply refuse 
to countenance the possibility of expressing such an 'ambiguous' 
literal.

This could be done in the DC version as follows:

aaa eg:prop _:1 .
_:1 rdf:label "10" .

where there is no rdf:type coming from the bNode.

Pat
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Received on Wednesday, 7 November 2001 17:41:01 EST

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