|In our discussions in the RIF WG on using RIF Core to represent the rules in the
OWL-RL profile, we could not perceive value for our user base in adopting owl:rational but noted that is already At Risk in the current OWL2 drafts. We also did not see value in requiring support for the string subtypes xsd:normalizedString, xsd:token, xsd:Name, xsd:NCName and xsd:NMTOKEN, though these are still under discussion.
This comment began within the context of the OWL-RL profile, however we would like to work towards a common set of datatypes for the semantic web.
PeterPatel-Schneider 16:55, 24 February 2009 (UTC)
[Draft Response for LC Comment 25:] RIF2
Dear Chris (and the RIF WG),
Thank you for your message
on the OWL 2 Web Ontology Language last call drafts.
The working group paid close attention to the datatypes that it supports. We examined the XML Schema datatypes to determine those that are acceptable for use within OWL. The datatypes xsd:normalizedString, xsd:token, xsd:Name, xsd:NCName, and xsd:NMTOKEN are simply derived from xsd:string and pose no problems for OWL 2. They are therefore included in the datatypes of OWL 2.
There was considerable discussion of owl:rational in the working group. There are natural uses for owl:rational (for example in recipes) but another reason to include owl:rational is to support n-ary datatypes with linear equations in data ranges. This optional extension to OWL 2 is in preparation; the current document can be found at http://www.w3.org/2007/OWL/wiki/Data_Range_Extension:_Linear_Equations
The OWL working group is interested in there being a set of Web compatible datatypes. Toward that end, the OWL working group will work with the RIF working group to describe and extend the set of datatypes supported by both OWL and RIF.
Please acknowledge receipt of this email to <mailto:email@example.com> (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.
Regards, Peter F. Patel-Schneider on behalf of the W3C OWL Working Group