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Re: Implementation report RDF Semantics

From: Ivan Herman <ivan@w3.org>
Date: Wed, 18 Dec 2013 09:27:42 +0100
Cc: Olivier Corby <olivier.corby@inria.fr>, W3C RDF WG <public-rdf-wg@w3.org>
Message-Id: <74A7C49B-3FD9-4DAE-BAA2-76FAF28FE788@w3.org>
To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
Thanks Peter

What effect does this have on the PR transition? Strictly speaking, we do not have two independent implementations for the complete test suite, ie, we have not fulfilled our exit criteria. Can there be a clear explanation that can be used to convince the Director that we can move ahead nevertheless? (I am looking for an elevator pitch equivalent of what you write below; something like "these tests are side-effect on the approach used for otherwise correct inference engines"...) One could actually argue whether these tests are correct in the first place if they are really dependent on the engines.

Thanks

Ivan



On 17 Dec 2013, at 21:55 , Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:

> Here is my analysis of the two "failures" from Corese.
> 
> datatypes-intensional-xsd-integer-string-incompatible
>    The test says that it is inconsistent to state that xsd:integer is a
>    subclass of xsd:string.
> 
> As most implementations directly implement datatype reasoning, they don't
> depend on this fact about integers and strings.  They can correctly reason
> about data values without noticing this invariant fact about the datatype
> classes themselves.
> 
> OWL implementations have to reason from facts like these, for example to
> correctly infer that the intersection of string and integer is empty, and so
> any property with both string and integer as a range can never have any
> fillers.
> 
> 
> xmlsch-02-whitespace-facet-3
>    Test that an explicit literal implies a blank filler that is a Literal
> 
> Most forward-chaining implementations of RDF reasoning do not directly
> perform complete entailment.  This kind of inference and perhaps one other
> is then handled by a separate portion of the system, which appears to not be
> part of the Corese that was used in the testing.
> 
> 
> So, Corese appears to have a good implementation of the core of forward-chaining RDF entailment, but does not directly implement two special cases (one related to datatype intensions and one related to datatype extensions and blank nodes).
> 
> 
> peter
> 
> 
> 
> 
> On 12/17/2013 10:00 AM, Ivan Herman wrote:
>> Looks much better! Thanks
>> 
>> Guys, we have two implementations of semantics. One is 100% (hurray Jan!), one is almost 100%. Peter, it would probably be good to have a good idea tomorrow why Corese fails on two tests and whether those are essential in terms of testing. Put it another way, can we try to go to PR based on these test results?
>> 
>> (We are still missing Michael Schreiber's report...)
>> 
>> Ivan
>> 
> 


----
Ivan Herman, W3C 
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Received on Wednesday, 18 December 2013 08:28:11 UTC

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