W3C home > Mailing lists > Public > www-rdf-logic@w3.org > September 2001

Re: model theory for RDF/S

From: Dan Connolly <connolly@w3.org>
Date: Fri, 28 Sep 2001 11:55:21 -0500
Message-ID: <3BB4AB79.B84C2FEE@w3.org>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
CC: phayes@ai.uwf.edu, www-rdf-logic@w3.org
"Peter F. Patel-Schneider" wrote:
> 
> From: Pat Hayes <phayes@ai.uwf.edu>
> Subject: Re: model theory for RDF/S
> Date: Fri, 28 Sep 2001 10:57:10 -0500
[...]
> > Ah, I had not thought of that in the DAML+OIL context.  Can you give
> > a simple example?
> 
> Consider the following, where one allows ranges to be XML Schema datatypes.
> (I hope that this is more-or-less valid N3.)
> 
> John age 0000025 .
> 
> Susan phone-number 0000025 .
> 
> age rdfs:range xsd:int .
> 
> phone-number rdfs:range xsd:string .
> 
> If there is a unique node for the literal 0000025, then what is the literal
> value that it maps to?  Is it the string "0000025" or the integer 25?

It's the string "0000025" and the age line is goofy;
it has to be written

 John age _:i25.
 _:i25 rdf:value "0000025".

There are no integer literals in N3/n-triples syntax (yet, anyway).
Even if we make up syntax for integer literals in n-triples
syntax, that won't change RDF 1.0 syntax, which has no
integer literal terms.

There may be integer literal values in the RDF model theory,
but they're not directly expressible in RDF/xml 1.0 syntax;
in RDF/xml 1.0 syntax, you can only say the equivalent of:

  the integer whose XML schema lexical representation is "0000025"

or rather:

  an integer whose XML schema lexical representation is "0000025"

where you can deduce that there is only one such integer
from axioms about xsd:int and rdf:value.

Actually, the syntax above only says the equivalent of

  something with rdf:value (aka XML schema lexical representation)
"0000025"

you can deduce that something is an integer, i.e.
 _:i25 rdf:type xsd:int.

from the range line and the age line.




-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Friday, 28 September 2001 12:55:26 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 2 March 2016 11:10:36 UTC