W3C home > Mailing lists > Public > public-owl-wg@w3.org > November 2007

Re: XML Schema datatypes

From: Jeff Z. Pan <jpan@csd.abdn.ac.uk>
Date: Thu, 15 Nov 2007 21:14:03 -0000 (GMT)
Message-ID: <1844.87.113.84.218.1195161243.squirrel@www.csd.abdn.ac.uk>
To: "Jeremy Carroll" <jjc@hpl.hp.com>
Cc: "Bijan Parsia" <bparsia@cs.man.ac.uk>, "Carsten Lutz" <clu@tcs.inf.tu-dresden.de>, "Web Ontology Language Working Group WG" <public-owl-wg@w3.org>


Hi all,

Interesting discussions. Some comments:

1) Mathematical datatypes and XML Schema datatypes are both
needed.

2) There exists a common subset of the two kinds of datatypes,
including xsd:Integer.

3) It might be an idea to consider additional mathematical
datatypes such as owl:real and owl:rational. The lexical forms of
these datatypes might need some work and discussions.

4) For rounded datatypes, users don't actually consider precise
equivalence, but approximate equivalence [1] instead, such as type
promotions used in XPath 2.0 [2]. Before using values of rounded
datatypes in reasoning, one might want to transform them back to
unrounded datatypes first.


Greetings,
Jeff

[1] http://www.w3.org/TR/swbp-xsch-datatypes/#sec-use-sparql

[2] http://www.w3.org/TR/xpath20/#promotion




On Thu, November 15, 2007 12:36 pm, Jeremy Carroll wrote:
>

> Skimming this thread somewhat - I believe the RDF Datatypes design is
> meant to be open to non-XML Schema datatypes defined by fiat, which may
> allow a WG to do what Bijan appears to be discussing - e.g. define an
> owl:integer an owl:real, owl:rational, owl:complex datatypes ....
>
>
> It may even allow for an owl:real datatype whose value space includes
> all the reals, even those that can't be written down.
>
> It would be another little project though, probably out-of-charter
> (certainly, if the timeline is taken into account).
>
>
> Jeremy
>
>
>
>
>
>
Received on Thursday, 15 November 2007 21:30:19 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 8 January 2008 14:13:27 GMT