RE: 'all resources' is not a set

So would it be useful to have, as a convenience, some kind of
"owl:intensionsl" attribute? 

> -----Original Message-----
> From: pat hayes [mailto:phayes@ihmc.us]
> Sent: Friday, September 26, 2003 8:42 PM
> To: LYNN,JAMES (HP-USA,ex1)
> Cc: public-sw-meaning@w3.org
> Subject: RE: 'all resources' is not a set
> 
> 
> >-----Original Message-----
> >From: pat hayes [mailto:phayes@ihmc.us]
> >Sent: Thursday, September 25, 2003 7:31 PM
> >To: Larry Masinter
> >Cc: public-sw-meaning@w3.org
> >Subject: Re: 'all resources' is not a set
> >
> >
> >
> >>>  Is the referent of
> >>>  'the morning star' and of 'the evening star' the same?
> >>>  Not defined.
> >
> >>  You chose a very bad example to make your case. The whole point of
> >>  the example is that it IS well-defined: the answer is yes, they do
> >>  have the same referent, viz. the planet Venus (but some 
> people don't
> >>  know that, hence the point of the example.)
> >
> >I may be a little unclear on how 'referent' is being used. 
> If the term
> >infers 'the actual object', as in Venus, I guess it's pretty clear.
> 
> Yes, that was the original idea of the example. BUt I agree you can 
> say that there are two intensional things which happen to have the 
> same extension, so that there are three distinct 'ideas' involved. If 
> you wanted to have an ontology about ideas rather than astronomy, 
> that would make sense.  Either way, however, you can use set theory 
> as a foundation. In fact, you can have both ways of thinking and 
> still use set theory, as long as you keep the various ideas clear.
> 
> >Perhaps
> >a better example of what confuses me is my congressman. My 
> intent is to
> >assert something about the representative like "he is 
> accountable for X", by
> >virtue of his role as a representative. In this case I don't 
> care that at
> >the moment my congressman is John Smith, since next year my 
> congressman may
> >be Jane Doe. But my assertion still stands. Is this notion 
> of role different
> >from the Venus example?
> 
> There are lots of examples like this: "The President" (who can change 
> from one guy to another every now and then, but is always The 
> President), or even things like "the main engine" which might be a 
> different piece of machinery after an overhaul but is still the main 
> engine.  You can take various positions on what 'things' like this 
> really are and how to best describe them, but they pose no particular 
> challenge to set theory as a foundation. For example, you can invent 
> a category of functional entities, and say that at any given time, a 
> functional entity is identical to a unique physical entity, but the 
> correspondence might change at various times. (Often, the times or 
> events have a special status, eg service outage or inauguration) . Or 
> you can invoke an overriding theory of 'continuants' or 'histories' 
> or 'eventualities' and base your ontology on those.  But again, all 
> of this can be accommodated within a set-theory foundation: in fact, 
> all of these have been used in first-order logic-based ontologies.
> 
> One way to conflate intermittent things like this to the Venus kind 
> of case is to use intensional individuals everywhere. What that means 
> in practice, however, is that you often need to say explicitly that 
> lots of normal things aren't particularly intensional and don't 
> change every now and then; and since there are often more of these 
> normal things than the other kind, it is usually easier to treat the 
> odd ones as oddities.
> 
> Pat
> 
> >James Lynn
> >Strategic Coordination - Enterprise Standards
> >HP Software Services
> >610 595 4995
> 
> 
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Received on Monday, 29 September 2003 09:13:30 UTC