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[Imports Task Force] revised imports spec

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Fri, 18 Apr 2008 11:51:09 -0400 (EDT)
Message-Id: <20080418.115109.247265858.pfps@research.bell-labs.com>
To: public-owl-wg@w3.org

I modified http://www.w3.org/2007/OWL/wiki/Imports a bit in light of the
discussion at the F2F.  On Monday, we could determine whether this
proposal is acceptable as a proposed resolution for ISSUE-21 and
ISSUE-24.  For easy reference, I have included the relevant part of the
Wiki page here.

Peter F. Patel-Schneider
Bell Labs Research

Basic idea:

Imports in OWL 2 are "by location": if an ontology O contains a
statement "Import( someURI )", then "someURI" specifies the location of
the imported ontology---that is, an OWL 2 implementation SHOULD access
the ontology at the location "someURI" using the standard Internet
protocols. In some cases, however, an application might want to retrieve
the imported ontology from some other location; this can be the case,
for example, in order to implement off-line caching or a staging
mechanism for ontologies prior to their publishing on the web. In this
case, an OWL 2 implementation MAY choose to replace or augment the
above described resolution mechanism with a mechanism that from
"someURI" determines how to find the ontology. In any case, the ontology
so found SHOULD have its ontologyURI equal to "someURI". 


Versioning is handled by a publishing methodology. The ontology with
ontology URI "someURI" is published at "someURI" *and* at another
location, which SHOULD be the value of an ontology annotation for
owl:versionInfo. When a new version of the ontology with ontology URI
"someURI" is created, it is published at "someURI" and also at a
version-specific location. Other ontologies can import from "someURI" if
the current version is wanted, or from the version-specific location if
a particular version is required. This has the side effect of loosening
name-location matching so that the ontology so found SHOULD have its
ontologyURI or an owl:versionInfo annotation value equal to

So the ontology

   Annotation(owl:versionInfo <http://example.com/ontology/v1/family>) ... )

would be published at both http://example.com/ontology/family and
http://example.com/ontology/v1/family. A new version 

   Annotation(owl:versionInfo <http://example.com/ontology/v2/family>) ... )

would be published at http://example.com/ontology/family, replacing the
version previously there, and also at

An ontology SHOULD NOT import multiple versions of the same ontology,
i.e., different ontology documents with the same ontology URI but that
do not share an owl:versionInfo annotation value.
Received on Friday, 18 April 2008 15:52:38 UTC

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