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OWL abstract syntax: -lite, -dl restrictions

From: Graham Klyne <gk@ninebynine.org>
Date: Tue, 06 May 2003 17:29:37 +0100
Message-Id: <5.1.0.14.2.20030506172150.0381a480@127.0.0.1>
To: public-webont-comments <public-webont-comments@w3.org>

With reference to:
   http://www.w3.org/TR/owl-semantics/syntax.html#2.3.1.2
and
   http://www.w3.org/TR/owl-semantics/syntax.html#2.3.2.3

I see that for OWL-lite:
[[
restriction ::= 'restriction(' datavaluedPropertyID 
dataRestrictionComponent ')'
             | 'restriction(' individualvaluedPropertyID 
objectRestrictionComponent ')'
]]

But for OWL-DL:
[[
restriction ::= 'restriction(' datavaluedPropertyID 
dataRestrictionComponent { dataRestrictionComponent } ')'
             | 'restriction(' individualvaluedPropertyID 
objectRestrictionComponent { objectRestrictionComponent } ')'
]]

Is it intended that a restriction may have only one component in OWL-lite?

This restriction (sic) seems rather pointless, as I think an axiom naming a 
class can be repeated with multiple single-component restrictions to 
achieve the same effect.

Also, I note that OWL-lite restrictions do not include the single-value 
form of restriction "Value( _ )".  Is this intended?

(I see no purpose in raising a formal issue for this.)

#g


-------------------
Graham Klyne
<GK@NineByNine.org>
PGP: 0FAA 69FF C083 000B A2E9  A131 01B9 1C7A DBCA CB5E
Received on Tuesday, 6 May 2003 16:25:11 GMT

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