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Re: Semantic E-mail

From: Laurian Gridinoc <laurian@gmail.com>
Date: Tue, 13 Jul 2004 08:48:48 +0000
Message-ID: <9782e33504071301486cb65374@mail.gmail.com>
To: www-rdf-interest@w3.org
Cc: jsled@asynchronous.org

On Sat, 10 Jul 2004 10:52:34 -0400, Josh Sled <jsled@asynchronous.org> wrote:
> It looks like both equivalentClass and equivalentProperty actually may
> not describe the relation you [Laurian] are after.  Specifically, it
> looks like both describe the state that the domain of the relations are
> identical, but _specifically_not_ that the concepts are the same.

I understand, thank you for the warning.

> sameAs is defined for what you're after ["The owl:sameAs statements are
> often used in defining mappings between ontologies"].
> However, when you apply owl:sameAs to classes and properties, you've
> started to treat classes as instances, which -- in my limited
> understanding -- passes you from the computationally-feasible world of
> OWL DL into the more heady world of OWL Full.  I still need to hit the
> DL books a couple more times to figure out exactly why.

In OWL Web Ontology Language (OWL Full/DL/Lite [1])
"RDF documents will generally be in OWL Full, unless they are
specifically constructed to be in OWL DL or Lite.
OWL Full and OWL DL support the same set of OWL language constructs.
Their difference lies in restrictions on the use of some of those
features and on the use of RDF features. OWL Full allows free mixing
of OWL with RDF Schema and, like RDF Schema, does not enforce a strict
separation of classes, properties, individuals and data values. OWL DL
puts constraints on the mixing with RDF and requires disjointness of
classes, properties, individuals and data values."

In  OWL Web Ontology Language Overview (OWL Lite Equality and Inequality [2])
"sameAs: Two individuals may be stated to be the same. These
constructs may be used to create a number of different names that
refer to the same individual. For example, the individual Deborah may
be stated to be the same individual as DeborahMcGuinness."

Then at OWL DL and Full Synopsis [3] 
"OWL DL and OWL Full language constructs that are in addition to or
expand those of OWL Lite"
where `sameAs' is not expanded, it remains to individuals domain...

More on individual vs. class (and DL vs. Full) is discussed at

I'm a bit lost... it seems that for the sake of partial understanding,
I have to jump from RDF Schema, not to OWL Lite or DL, but to OWL
[1] http://www.w3.org/TR/owl-ref/#Sublanguages
[2] http://www.w3.org/TR/2004/REC-owl-features-20040210/#s3.1
[3] http://www.w3.org/TR/2004/REC-owl-features-20040210/#s2.2

Thank you,
Laurian Gridinoc
Chief Developer
Received on Tuesday, 13 July 2004 04:57:42 UTC

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