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Re: Implementation report RDF Semantics

From: Sandro Hawke <sandro@w3.org>
Date: Wed, 18 Dec 2013 07:12:18 -0500
To: Ivan Herman <ivan@w3.org>,"Peter F. Patel-Schneider" <pfpschneider@gmail.com>
CC: Olivier Corby <olivier.corby@inria.fr>,W3C RDF WG <public-rdf-wg@w3.org>
Message-ID: <266670c1-efcb-4a61-8667-5df05e1a1732@email.android.com>
Ivan Herman <ivan@w3.org> wrote:
>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.
>

One procedural technique would be to rescind those tests as not helpful to interoperability.

    - Sandro

>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 
>Digital Publishing Activity Lead
>Home: http://www.w3.org/People/Ivan/
>mobile: +31-641044153
>GPG: 0x343F1A3D
>FOAF: http://www.ivan-herman.net/foaf
Received on Wednesday, 18 December 2013 12:12:27 UTC

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