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Re: simplified datatyping proposal

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Wed, 20 Feb 2002 13:22:32 +0200
To: Pat Hayes <phayes@ai.uwf.edu>, RDF Core <w3c-rdfcore-wg@w3.org>
Message-ID: <B8995398.F0E7%patrick.stickler@nokia.com>
On 2002-02-20 6:11, "ext Pat Hayes" <phayes@ai.uwf.edu> wrote:

> Guys, Ive put up a quick draft of a simplified version of the
> datatyping proposal at
> http://www.coginst.uwf.edu/users/phayes/simpledatatype

(the URL is missing the final '.html')

I can live with this.


One final plea...

I think that while it is agreed that no matter
where a literal occurs in the graph, whether inline or
in a datatyping idiom, it is just a literal -- it would
be useful to provide the ability to interpret an inline
literal as a lexical form such that there simply is not an
explicit denotation of the value in the graph.


   Jenny ex:age "15" .

without datatyping asserted by any range statements
just means that "15" is interpreted as "15".

Whereas all of the following mean that "15" is 15, insofar
as interpretation by an application is concerned, not that
15 has any explicit denotation in the graph in all cases
(though it does in all of the bNode idioms):

   Jenny ex:age "15" .
   ex:age rdfs:drange xsd:integer .

   Jenny ex:age _:1 .
   _:1 rdfs:dlex "15" .
   ex:age rdfs:drange xsd:integer .

   Jenny ex:age _:1 .
   _:1 xsd:integer "15" .

   Jenny ex:age _:1 .
   _:1 rdfs:dlex "15" .
   _:1 rdfs:dtype xsd:integer .

Likewise, I think it's fair to interpret the first
range constraint above as meaning that if the property
value of ex:age is a literal, then it must be a member
of the lexical space of the datatype. If the property
value is a bNode, it denotes a member of the value
space of the datatype.

If one wishes to also exclude value bNodes for a given
property, then in addition to the rdfs:drange constraint
one can add

   ex:age rdfs:range rdfs:Literal .

and if one wishes to exclude inline idioms, then add

   ex:age rdfs:range rdfs:Resource .

and that is that.

Since multiple ranges are treated as an intersection, the
intersection of ddd.(val U lex) and rdfs:Literal is ddd.lex
and the intersection of ddd.(val U lex) and rdfs:Resource
is ddd.val.

I think that the ability to use the inline/S-B idiom
with datatyping will be much appreciated by users, and
rejection of the *spirit* and *intent* of the above
would be a great shame.



Patrick Stickler              Phone: +358 50 483 9453
Senior Research Scientist     Fax:   +358 7180 35409
Nokia Research Center         Email: patrick.stickler@nokia.com
Received on Wednesday, 20 February 2002 06:21:00 UTC

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