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draft response for 43b ZW3b

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Tue, 24 Feb 2009 10:42:50 -0500 (EST)
Message-Id: <20090224.104250.20953023.pfps@research.bell-labs.com>
To: public-owl-wg@w3.org
[Draft Response for LC Comment 43b:] ZW2b

Dear Zhe,

Thank you for your message
on the OWL 2 Web Ontology Language last call drafts.
Your message contains multiple sections, affecting more than one
document, and will thus generate multiple replies.  This response
is for sections 4 and 8 about the datatypes in OWL 2 RL.

We have adjusted the datatypes of OWL 2 RL to include those XML Schema
datatypes that are derived from xsd:string and xsd:integer, including
xsd:positiveInteger.  These were excluded from OWL 2 RL because of a
mistaken analogy with OWL 2 EL and OWL 2 QL, namely that intersection of
value spaces must be either empty or infinite to maintain the desired
properties of the profile.  It turns out that this is not needed in OWL
2 RL to obtain its desired computational properties.  As any OWL 2 RL
tool has to process xsd: string and xsd:integer, the added
implementation burden to support these datatypes is negligible.

The situation with owl:rational and owl:real is different.  The working
group has received complaints that implementing
these datatypes may require significant effort on top of a rule
reasoner.  Therefore owl:rational and owl:real have been removed from
OWL 2 RL.  This possibility was mentioned in Feature At Risk #2.

The diffs for these changes can be found at

The working group notes that Oracle has also brought up concerns with
the treatment of xsd:float and xsd:double.  These two datatypes are not
currently part of OWL 2 RL.   If this situation changes the working
group will communicate with you.

Please acknowledge receipt of this email to
<mailto:public-owl-comments@w3.org> (replying to this email should
suffice). In your acknowledgment please let us know whether or not you
are satisfied with the working group's response to your comment. 

Peter F. Patel-Schneider
on behalf of the W3C OWL Working Group 
Received on Tuesday, 24 February 2009 15:43:09 UTC

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