- From: Jeremy Carroll <jjc@HPLB.HPL.HP.COM>
- Date: Tue, 23 Apr 2002 15:21:05 +0100
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- Cc: <www-webont-wg@w3.org>
> Well, I have not yet seen a worked-out version of the solipsistic stuff. > In particular, how are conditionally-existing classes handled in this > approach. > > Consider the following query: > John rdf:type _:1 . > _:1 daml:onProperty foo . > _:1 daml:toClass daml:Restriction . > John rdf:type _:2 . > _:2 daml:onProperty foo . > _:2 daml:hasClass _:3 . > _:3 daml:OneOf _:4 . > _:4 daml:first _:R1 . > _:4 daml:rest _:5 . > _:5 daml:first _:R2 . > _:5 daml:rest daml:nil . > > Which restrictions are to be added to the premises for this sort of query? > Of course, it doesn't matter here, because neither _:R1 nor _:R2 are > interesting, but a larger example could be constructed where it would > matter. Yes that's a nice example. If I have understood, you have set it up so that either _:R1 or _:R2 is a daml:Restriction. Extending the example and assuming the triples are not dark and the implicit consequences carry the semantics then it is difficult (read "not realistic with reasonable termination") to implement this. To some extent this difficulty is the case whenever we set up a disjunction, and users need to have some sort of expectation that not everything that they might say is necessarily going to be soluble within reasonable time. I can see that examples where the disjunction is within the ontology machinery are much more likely to lead to excessive search space. Jeremy
Received on Tuesday, 23 April 2002 10:21:43 UTC