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Re: Some advice on inferring negated properties

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Thu, 16 Aug 2007 20:39:39 +0100
Message-Id: <D22A9F2E-81A4-4D88-9C20-FC2F8E3DF64B@cs.man.ac.uk>
Cc: "Matt Williams" <matthew.williams@cancer.org.uk>, "Owl Dev" <public-owl-dev@w3.org>
To: "Swanson, Tim" <tim.swanson@semanticarts.com>

On Aug 16, 2007, at 8:28 PM, Swanson, Tim wrote:

> Bijan,
> Thanks again. I think you're right, the misunderstanding goes back to
> talking at cross-purposes. I have just one more question.
>>> (Admittedly, this is not the same thing as "directly" checking for
>> the
>>> negative entailment, since it relies on the user's understanding of
>>> OWL
>>> semantics to make the jump from membership in the above class to the
>>> negative entailment.)
>> It's not a negative entailment (which for me means a *failure* to
>> entail) but an entailment of a negation, but yes. For Matt's purpose
>> this might be fine. OWL 1.1 statement entailment shall be added to
>> Pellet in due course (esp to support SPARQL). One could, of course,
>> write such a wrapper.
> "negative entailment" = "failure to entail" (i.e. still unknown in the
> open world)

More typically known as "non-entailment" (e.g., non-subsumption as  

I've never specifically heard "negative entailment" before, so I see  
I read it as a variant of "non-entailment".

> "entailment of a negation" = "entailing that something is  
> untrue" (i.e.
> known to be false)

Well, the *negation* is true (entailed), but of course the negated  
sentence is false.

> Is this the accepted language? (If so, I need to re-write some of our
> in-house documents to comply with it.)

I feel that the above is standard.

Received on Thursday, 16 August 2007 19:39:51 UTC

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