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Re: Agenda/Logistics, Oct 2 telecon

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Wed, 01 Oct 2003 09:04:02 -0400 (EDT)
Message-Id: <20031001.090402.55195678.pfps@research.bell-labs.com>
To: jjc@hpl.hp.com
Cc: www-webont-wg@w3.org

I will not be able to make the October 2 teleconference.  Here are my
thoughts on the potential topics that impact S&AS.  I give my proxy to Ian
Horrocks for any formal votes required.

peter


[The numbering here is consistent with that in Jeremy's message.]


B1/ Untyped Annotation values

   Annotation values can be ``bare'' URI references, for which no other
   information is known.  This ability was included to allow things like
   the DC properties to work easily as annotation properties.

   RESOLUTION:  No change to S&AS to be made here.  Other OWL documents
		need to be investigated to see whether they forbid such
		annotation values. 

   NOTE:  This is different from the change that Jeremy is advocating. 

B2/ Untyped Types in Typed Literals

   The URI reference in a typed literal does not currently need to be typed
   as a datatype.   This is mostly a holdover from the past but it does
   allow for ``random'' junk in typed literals, which may or may not be a
   good thing.  There is very little use for such typed literals, as there
   is no way in OWL to effectively use datatypes that are not in the
   approved list datatypes, which are all built in anyway.

   RESOLUTION:  No change to S&AS to be made here.  Other OWL documents
		need to be investigated to see whether they forbid such
		types. 

C/ Semantic layering bug

   The change to allow optional ontology type triples breaks semantic
   layering at bit more.  (It was sort of broken in this area, but I think
   everything might have worked anyway, due to some fortuitous
   circumstances.) 

   Fix:  1/ Extend OWL abstract consistency and entailment to also allow
	    axioms and facts outside of ontologies.
	 2/ Extend OWL satisfaction of an abstract ontology to require that
	    the ontology be of type owl:Ontology.
	 3/ Extend the mapping to triples to allow for axioms and facts
	    outside of an ontology. 
	 4/ Make the typing triple mandatory for unnamed ontologies.

   RESOLUTION:  Approve the above fix.  The only documents that should need
		changing are S&AS and Test.  I accept an action to make the
		changes to S&AS.

   NOTE:  This effectively replaces the change of 18 September that made
	  rdf:type triples optional for unnamed ontologies, but gets the
	  same effect by allowing axioms and facts outside of ontologies.

E/ Loops in owl:equivalentClass

   The wording does not currently talk about loops.  Undirected graphs do
   not need to be loop free.  Loops are explicitly forbidden in the mapping
   to owl:disjointWith.  I suggest that no change be made.

   RESOLUTION:  No change to the OWL specification to be made here.  Two
		tests showing that loops are allowed (one with only one
		node in the graph) to be added to the test suite.  A test
		showing that loops are not allowed for owl:disjointWith to
		be added to the test suite.
Received on Wednesday, 1 October 2003 09:04:31 GMT

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