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RE: SEM: semantics for current proposal

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 21 Mar 2002 12:17:51 -0500
To: ziv@unicorn.com
Cc: www-webont-wg@w3.org
Message-Id: <20020321121751I.pfps@research.bell-labs.com>
From: "Ziv Hellman" <ziv@unicorn.com>
Subject: RE: SEM: semantics for current proposal
Date: Thu, 21 Mar 2002 19:13:59 +0200

> I have a question regarding the interaction of uniquely identifying
> properties and cardinalities in OWL. 
> 
> That is, suppose that a property p has  min cardinality 3 and max
> cardinality 5, is defined to be uniquely identifying, and we have two
> instances i and j.
> 
> Let the instances associated with i through p be  { a, b, c }
> and suppose now one wishes to associated with instance j, through p, the
> instances { c d e f }. Is this problematic because c is in the range of
> both i and j, or is this allowed because {a b c} != {c d e f} ?

Yes, this is a contradiction, provided that i ~= j.
uniquelyidentifying means that the converse is functional, so if i ~= j then
c will have two values for the converse of p.

peter
Received on Thursday, 21 March 2002 12:19:38 GMT

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