Re: Can there be a URI for the concepts "I", "you", "this", "it", "here", "there", "now", etc.?

John Black wrote:
>> <> indexicals:isBeingReadBy _:you .
>> <> indexicals:isBeingReadAtLocation _:here .
>> (then you go on to make assertions about _:you and _:here.)
>>
>> where <> is the URI for the document itself,
> 
> I think it is ironic that your example of how to avoid the need for
> indexicals uses the one indexical URI that RDF can't seem to do without,
> that is: <>. or rdf:about="".  Don't oblivious applications use this
> indexical?

Ah, but it's not indexical (in the relevant sense).  See, that's what we
get for having syntactic shortcuts and long specs.  <> and rdf:about=""
are both necessarily interpreted as relative URIs, relative to the base
URI of the document being parsed.  Since they're blank, they are
evaluated as the base URI itself.  Provided the parser knows the URI of
the document it is loading, it sees those as the URI of the document.
(This is the same mechanism behind rdf:about="#abc".)

The reason this is OK is that this behavior is mandated in the RDF/XML
specification, so no application that conforms to the spec can be
oblivious to that.

But, actually, the use of <> in my example was a bit arbitrary.  I could
have also written

_:you rdf:type indexicals:TheReadingAgent .

(or any number of other things).

-- 
- Josh Tauberer

http://razor.occams.info

"Yields falsehood when preceded by its quotation!  Yields
falsehood when preceded by its quotation!" Achilles to
Tortoise (in "Gödel, Escher, Bach" by Douglas Hofstadter)

Received on Monday, 18 December 2006 23:34:07 UTC