RE: OWL 2.0 ...

This strikes me as an exquisitely ontological, or if your prefer
domain-sensitive, determination: There are plenty of individuals (in the
sense in which individuals are in pricniple distinct from classes) that
would not have spatio temporal presence such as you describe. 
 
There can be abstract individuals that have no particular location,
though perhaps a "lifetime": ordinary examples would be, under plausible
assumptions, Beethoven's 5th symphony and the "Crusoe." 
 
There can be individuals that have perhaps location in abstract space,
but no lifetime: the Equator, or the North Pole.  All this might be in
dispute, of course.  The point is I don't think this belongs in a
language's specification. 


________________________________

	From: public-owl-dev-request@w3.org
[mailto:public-owl-dev-request@w3.org] On Behalf Of Hans Teijgeler
	Sent: Tuesday, April 12, 2005 4:25 PM
	To: public-owl-dev@w3.org
	Cc: Pruijn, Peter Paul; Valen-Sendstad, Magne
	Subject: Re: OWL 2.0 ...
	
	
	Hi Jim,
	 
	What I dearly miss in OWL is the concept of a spatio-temporal
ontology, where a clear distinction is made between:
	-  "class" as a type with criteria for membership
	-  "individual" existing in space and time
	 
	A class can be a specialization (subClassOf) of one or more
other classes.
	 
	An individual can be a member of one or more classes, and that
membership starts at some point in time and ends at a later point in
time.
	 
	An individual can be composed of other individuals, connected to
other individuals, contain other individuals, identified with (e.g.) a
tag number, part number, SSN, etc., and these Properties are starting to
be valid at some point in time and ending at some later point in time.
	 
	An individual has a limited lifetime, a class is eternal (the
class PlayStation existed already at the Big Bang, only there were no
people around to discover it, and at that time there were no members
yet, just as at present there are no members yet of the class
"commercial fusion reactor").
	 
	The lack of distinction to me, coming from my paradigm, is
bewildering when I try to understand example ontology listings. When
reading the "wine" example in the Guide I have difficulty to understand
when a kind of wine is meant and when actual wine that you can pour in
your glass.
	 
	In the eBusiness catalogs the class-only concept works, but in
asset management not, at least not with great difficulty.
	 
	This is probably not the kind of input you had in mind, but to
us this is important.
	 
	Regards,
	Hans
	 
	____________________________
	Hans Teijgeler
	co-author of ISO 15926-2
<http://www.infowebml.ws/ECM4.5/ECM4.5.html> 
	author of ISO 15926-7
	website www.InfowebML.ws <http://www.infowebml.ws/> 
	e-mail hans.teijgeler@quicknet.nl
	phone +31-72-509 2005