[DL] dl systems with concrete domain

[Ronald Cornet]

Louis,

Good to have "naive" questions on this list. Not that I'm sure about the 
answer, though.

My guess is that this involves second order logic.
Your rule (father is older than son) is comparable to : a jealous-man has 
less cars than its neighbor.
This also cannot be expressed in DL, being limited to FOL (with some 
extension eventually).

Hope this helps, and more, I hope to be correct ;-)

Ronald

At 00:40 23-04-03 +0200, Louis.Chevallier wrote:
>Sorry for the naive question, but it is buzzing me for so long time:
>
>Is there any real DL systems currently available that  implement concrete 
>domain together with reasonnably expressive logics and that allow 
>"attribute chains".
>
>I am thinking about seemingly simple need like the need of stating that 
>any father is older than his son(s) A statement that would involve a 
>hasAge real attribute.
>
>Racer does propose real attribute but it seems that some mysterious 
>difficulties prevent me from entering such constraints
>
>Any clue?
>
>Thanks
>
>louis


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Ronald Cornet, M.Sc.                        email: R.Cornet at amc.uva.nl
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