work on OWL semantics [was Re: WOWG: agenda Oct 24 telecon]

From: Guus Schreiber <schreiber@swi.psy.uva.nl>
Subject: WOWG: agenda Oct 24 telecon
Date: Wed, 23 Oct 2002 16:58:46 +0200

> ACTION Peter Patel-Schneider/Pat Hayes: draft OWL semantics,
>    including the "2 technical bits" [should also address issues 4.6,
>    5.9, 5.22]

For those of you who care, a proof (mostly unchecked) that the two OWL
semantics are the same on Fast OWL can be found (for now) in
  http://www-db.research.bell-labs.com/user/pfps/temp/owl/correspond.html

This correspondence breaks down in the presence of unrestricted
owl:equivalentTo (issue 4.6).  

The semantics for Fast OWL uses owl:Class and requires that it be different
from rdfs:Class.


By the way, there are two possibilities for malformed restrictions (issue
5.9).

The DAML+OIL stance is that restrictions with missing pieces have no
additional meaning and that restrictions with multiple pieces have as class
extension the extension of each possible way to create a restriction from
the pieces.

The current semantics makes restrictions with missing pieces have no
additional meaning.  Restrictions with multiple onProperties make the
properties be the same.  Restrictions with multiple other pieces (i.e., a
allValuesFrom and a someValuesFrom) have as class extension the extension
of each of them.

peter

Received on Wednesday, 23 October 2002 15:54:42 UTC