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Re: Datatype test cases: important ones (please have a look)

From: Graham Klyne <GK@NineByNine.org>
Date: Mon, 25 Nov 2002 09:48:54 +0000
Message-Id: <5.1.0.14.2.20021125094407.0429c970@127.0.0.1>
To: Jan Grant <Jan.Grant@bristol.ac.uk>
Cc: RDFCore Working Group <w3c-rdfcore-wg@w3.org>

[Catching up...]

I find this a little confusing:

At 02:49 PM 11/20/02 +0000, Jan Grant wrote:
>A "negative entailment test" passes if:
>
>         - P has no valid interpretations (contains a semantic error) OR
>         - P is ok but does not entail C.

In that if P has no valid interpretations I'd expect the entailment to pass 
for any consequence.

Would it not be clearer to split this into two kinds of test:

(a) a semantic invalidity test, in which we can assert that some expression 
has no valid interpretations, and

(b) a negative entailment test:  P has valid interpretations and does not 
entail C.

Or, maybe it's too late to go here?

Looking ahead, I see:
>D2 has semantic errors (encoded by -ve ent test, D2 -/-> E)

This seems unexpected on two counts (E is always true, surely?).

I note your desire to avoid a notional always-false document F - I think I 
would prefer that approach rather than  the modified notion of entailment 
you use (but don't feel strongly enough to argue about it).  I guess your 
concern is that there is no way within the stated semantic constraints for 
RDF to construct a document that is false under every possible interpretation?

#g


-------------------
Graham Klyne
<GK@NineByNine.org>
Received on Monday, 25 November 2002 09:35:35 EST

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