- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Fri, 09 May 2003 14:55:29 -0400 (EDT)
- To: gk@ninebynine.org
- Cc: public-webont-comments@w3.org
From: Graham Klyne <gk@ninebynine.org>
Subject: Owl abstract syntax, equivalent classes
Date: Tue, 06 May 2003 17:07:03 +0100
> With reference to:
> http://www.w3.org/TR/owl-semantics/syntax.html#2.3.2.1
>
> I see:
> [[
> axiom ::= 'DisjointClasses(' description description { description } ')'
> | 'EquivalentClasses(' description { description } ')'
> | 'SubClassOf(' description description ')'
> ]]
>
> which appears to admit "EquivalentClasses( description )" as a valid axiom.
>
> Is this correct? If so, what does it mean? I'm guessing there's a missing
> "description" in the EquivalentClasses production. (Assuming this is so, I
> see no cause to raise a formal comment.)
This is correct. Allowing EquivalentClasses( description ) means that
blank node descriptions with no connections to other descriptions are
allowed, as per a request from Jeremy Carroll. Such unconnected
blank node descriptions have no semantic import.
Peter F. Patel-Schneider
Bell Labs Research
Lucent Technologies
Received on Friday, 9 May 2003 14:55:40 UTC