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Re: Input sought on datatyping tradeoff

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Sat, 13 Jul 2002 10:08:59 +0100
Message-Id: <>
To: Drew McDermott <drew.mcdermott@yale.edu>, www-rdf-logic@w3.org

At 17:44 12/07/2002 -0400, Drew McDermott wrote:


>    ....
>    Because the A tests have no range constraint.  We either have to decide
>    that literals are self denoting - they always denote themselves in which
>    case the answer to D must be NO, or their denotation depends on a range
>    constraint in which case the answer to A must be NO.
>It could be "I don't know."

Yes that's right, and given the way the question is put, the answer is then 
NO, you cannot conclude they are equal.  It might have been clearer if the 
question explicitly allowed for that possibility, but I don't want to 
change it now as to do so may cause confusion.

>    [Jonathan]
>    >note that "value-equal" might be non-monotonic if the <rdfs:range> 
> propery
>    >got detatched from the other triples
>    [Brian]
>    that would not be non-monotonic - if you remove a triple then of 
> course you
>    are free to remove some inferences that depend on it.  My 
> understanding of
>    non monotonicity is that you must never withdraw an inference because of
>    adding new triples.
>Don't you mean "monotonicity" in that last sentence?

Oops, just so.  :)  Whats the symbol for an embarrassed smile?  :-?

>It seems to me that Jonathan has a strong argument.  If the inferences
>from a triple must stand when new triples are added, and if the answer
>to Test A must be either Yes or No, then it can only be Yes.

Given the way the question is phrased, "NO because it can't tell if they or 
not" is an ok answer.

Received on Saturday, 13 July 2002 05:11:11 UTC

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