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RE: OWL DL extension question

From: Conrad Bock <conrad.bock@nist.gov>
Date: Wed, 11 Apr 2007 13:54:40 -0400
To: "'Evren Sirin'" <evren@clarkparsia.com>
Cc: <public-owl-dev@w3.org>, "'Evan Wallace'" <evan.wallace@nist.gov>
Message-ID: <03fb01c77c62$7b145dc0$b3200681@MEL.NIST.GOV>

Evren,

 > > Was wondering if anyone is looking into whether this fragment can
 > > be added tractably to OWL DL (1.0):

 > >   (forall (x y z)
 > >      (if (and (P x y)
 > >               (R x z))
 > >          (S y z)))
 > >
 > > For example, the uncles of my children include all my brothers
 > > (P=children, R=brothers, S=uncles).

 > You can turn the antecedent into a property chain using the 
 > inverse of P 
 > and then use the standard complex role inclusions of OWL 1.1 as:

 > SubObjectPropertyOf(SubObjectPropertyChain(InverseObjectPrope
 > rty(children) 
 > brothers) uncles)

Great, thanks.

 > provided that the restrictions described at [1] are not violated.

Do you happen to know if anyone has shown these to be the maximal
restrictions, ie, any loosening of them will cause undecidability?  In
particular, is the regularity restriction maximal?

Conrad


PS: I assume the first set of bullets are disjunctive, but the text
doesn't say this explicitly.
Received on Wednesday, 11 April 2007 17:55:02 GMT

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