Re: SEM: Face-to-Face version of approaches document

• From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
• Date: Fri, 05 Apr 2002 15:52:50 -0500
• To: heflin@cse.lehigh.edu
• Cc: www-webont-wg@w3.org
• Message-Id: <20020405155250P.pfps@research.bell-labs.com>

From: Jeff Heflin <heflin@cse.lehigh.edu>
Subject: Re: SEM: Face-to-Face version of approaches document
Date: Fri, 05 Apr 2002 11:52:34 -0500

> 2) I don't fully understand the implications of the issue, but I find
> the particular example undesirable. Could you describe the basic issue a
> little more formally?

A fully formal description would be very long, but consider the following,
using an informal syntax:

  (instance John (and (all foo TransitiveProperty)
		      (some foo (set friend enemy))))
  (subProperty friend knows)
  (subProperty enemy knows)
  (friend Mary Bill)
  (friend Bill Susan)
  (enemy Mary Jeff)
  (enemy Jeff Susan)

one would think that this implies

  (knows Mary Susan)

because either friend or enemy is a TransitiveProperty.


peter

Received on Friday, 5 April 2002 15:53:37 UTC