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RE: SEM: semantics for current proposal (why R disjoint V?)

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Thu, 18 Apr 2002 10:34:06 -0500
Message-Id: <p0510151fb8e497befd2e@[65.217.30.94]>
To: Ian Horrocks <horrocks@cs.man.ac.uk>
Cc: www-webont-wg@w3.org
>On April 8, Pat Hayes writes:
>>  >On March 22, Jeremy Carroll writes:
>>  >>  >
>>  >>  > [1]
>>  >> 
>>http://www-lti.informatik.rwth-aachen.de/~clu/papers/archive/lutzdiss.pdf
>>  >>
>>  >>
>>  >>
>>  >>  Ian,
>>  >>
>>  >>  I don't think I have time to read 225 pages ... :(
>>  >>
>>  >>  Is there a shorter version of the central argument?
>>  >
>>  >The key point is that without separation of properties, when you
>>  >negate restriction classes, e.g., (hasClass age >=21) you get (toClass
>>  >age (union <21 Thing)), which breaks the separation of the datatype
>>  >and abstract domains which is itself required in order to allow
>>  >datatype reasoning to be separated from class based reasoning.
>>
>>  Wait. That seems circular. Isn't this supposed to be an argument for
>>  why we need to separate datatype reasoning from class-based reasoning
>>  in the first place? Suppose we just say that, OK, they are not
>>  separated. Then the above argument says that if we have negation then
>>  they are not separated. But we already knew that, right?
>
>The question I thought I was answering was, why separate properties as
>well as domains?

Ah, OK, I didnt follow that part.

>The above argument says that you need to separate
>the properties in order to keep the domains separate.

Right.

Pat


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Received on Thursday, 18 April 2002 11:34:12 GMT

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