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Re: the precondition property in OWL-S 1.0

From: Bijan Parsia <bparsia@isr.umd.edu>
Date: Sun, 9 Nov 2003 00:21:45 -0500
Cc: public-sws-ig@w3.org
To: Drew McDermott <drew.mcdermott@yale.edu>
Message-Id: <9C4F57BA-1274-11D8-A350-0003936A0B26@isr.umd.edu>

On Saturday, November 8, 2003, at 10:41 PM, Drew McDermott wrote:
>    [Bijan Parsia]
>    There's two aspects of a precondition, its own logical form, and the
>    fact that it is embedded in larger conditional (effectively). So, 
> if a
>    precondition is that <<My Credit line is greater than 1000>>, the 
> form
>    of that assertion *could* just be a regular condition. and arguably
>    should be. It's the *relationship* between that formula and the 
> process
>    that adds the extra semantics, much like putting a formula in the 
> body
>    of a rule "changes" its semantics (*if* it is co-true with the other
>    atoms, then the consequential atoms must be true).
> Actually, when semantics is done right, the context of a formula
> doesn't add any "extra semantics."  All the meaning of (if P Q) can be
> factored into the meaning of P, the meaning of Q, and the meaning of
> (if _ _).

Obviously, I agree. :)

> I sort of thought the Precondition class was essentially a typo -- a
> side effect of too many cooks stirring that particular soup.  Why are
> we defending its existence?

Dunno. :)


Hmm. Well, I guess merely having a named class for the class expression 
Condition & someValuesFrom inv(hasPrecondition, Process) isn't 

Bijan Parsia.
Received on Sunday, 9 November 2003 00:20:36 UTC

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