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Re: Jena implementation report plans

From: Dave Reynolds <der@hplb.hpl.hp.com>
Date: Thu, 04 Sep 2003 15:29:49 +0100
Message-ID: <3F574C5D.7060507@hplb.hpl.hp.com>
To: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Cc: www-webont-wg@w3.org

Jeremy Carroll wrote:

> We do not have a component directly corresponding to an OWL Consistency 
> Checker.

To expand on this slightly. The rule-based reasoner does have a "validation" 
operation but it is incomplete. We have yet to check whether enough of the 
consistency tests can be handled to make reporting results on those tests 
worthwhile.

> In the next few days, we plan to make a comment concerning the 
> comprehension axioms, suggesting that more tests should be added to 
> permit testing the semantics of some features without testing the 
> comprehension axioms. (We already have modified forms of some of the 
> tests which we could contribute to the test suite).

Let me make a preliminary comment now, to test reaction.

Several of the test cases for axioms such as the cardinality axioms implicitly 
require comprehension axioms as well. This raises issues with systems, such as 
Jena, which expose inference services at the RDF level.

To be concrete, consider, for example, FunctionalProperty/Manifest005. Using 
abstract syntax for conciseness, this is currently formulated as:

  Premises005:
   Individual(foo:object, type(owl:Thing))
   ObjectProperty(foo:prop, Functional)

  Conclusions005:
   Individual(foo:object, type(owl:Thing)
              type(restriction(foo:prop, maxCardinality(1))))

An alternative formulation of this test case is:

  Premises005-mod:
   Individual(foo:object, type(owl:Thing))
   ObjectProperty(foo:prop, Functional)
   Class(foo:compClass1 complete
               restriction(foo:prop, maxCardinality(1)))

  Conclusions005-mod:
   Individual(foo:object, type(owl:Thing) type(owl:compClass1))

This alternative formulation seems to be testing the same relationship between 
functional properties and max cardinality restrictions but is in a form that can 
be trivially mechanically translated into a query for an RDF API.

Approximately 10 test cases could be usefully reformulated this way.

Possible responses to this comment include:
1. Modify some of test cases to this simple-conclusion style.
2. Augment the test cases by duplicates in this style.
3. Ignore it and leave the test cases as is.

Dave
Received on Thursday, 4 September 2003 10:58:35 GMT

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