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Re: simple entailments for numerals

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Wed, 23 Oct 2002 08:20:18 +0300
Message-ID: <004701c27a53$e055aa60$1381720a@NOE.Nokia.com>
To: "w3c-rdfcore-wg" <w3c-rdfcore-wg@w3.org>, "ext Jos De_Roo" <jos.deroo.jd@belgium.agfa.com>



[Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, patrick.stickler@nokia.com]


----- Original Message ----- 
From: "ext Jos De_Roo" <jos.deroo.jd@belgium.agfa.com>
To: "w3c-rdfcore-wg" <w3c-rdfcore-wg@w3.org>
Sent: 22 October, 2002 23:18
Subject: simple entailments for numerals


> 
> [just to report some experience]
> it seems to me that numbers are important
> so in
>   :Jenny :age '10' .
> the '10' (which is *not* the "10" but a
> syntactic shorthand for xsd:decimal"10" or
> any subclassed value of it)
> denotes the number 10
> and so
>   :Jenny :age '10' .
> simple-entails
>   :Jenny :age '+1E1' .

Yes and no. This only works IFF the subclass of xsd:decimal
has both a lexical space that is a proper subset of xsd:decimal
and a L2V mapping that is compatable to that of xsd:decimal.

If you had a subclass (e.g. Scheme language integers or binary
encoded integers) where the lexical space or L2V mapping diverges
from xsd:decimal, then you would not be able to reliably represent
values in terms of that subtype using the simple notatation.

See http://www-nrc.nokia.com/sw/datatypes.zip for code that bears
this out.

Thus, in actuality, the 'LLL' notation would *only* map to 
xsd:decimal"LLL" and to no other datatype whatsoever.

So yes, 'LLL' would entail any possible xsd:decimal variant
lexical representation synonymous with "LLL" but subclasses don't
actually enter into the picture.

And as an aside, if you're talking about an extension to N3, as
a form of syntactic sugar, fine, but RDF has no built in datatypes
(other than perhaps rdfs:StringLiteral and rdfs:XMLLiteral) so
the default mapping of 'LLL' to xsd:decimal"LLL" would not be
defined for RDF/XML or N-Triples.

Patrick
Received on Wednesday, 23 October 2002 01:20:26 EDT

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