Re: Detecting cycles in OWL

Il giorno 5 mag 2020, alle ore 02:54, Peter F. Patel-Schneider <pfpschneider@gmail.com<mailto:pfpschneider@gmail.com>> ha scritto:
Yes, yes, for any particular OWL derivation you could write a SPARQL CONSTRUCT
query that mimics that proof, but there are an infinite number of these
derivations.

More specifically, for each of the infinitely many OWL ontology structures, there are infinitely many SPARQL CONSTRUCT queries, which compute the (infinitely big) deductive closure for that OWL ontology structure. Some of these SPARQL CONSTRUCT queries may be infinite themselves.
And even if we are happy to have only an incomplete version of the reasoner, we need a complete reasoner to find and/or validate the finitely many SPARQL CONSTRUCT queries.

Also, I'm not sure that SPARQL CONSTRUCT queries are able to represent arbitrary graph transformations needed to express all OWL derivations; it may be the case but it should be proved.

cheers
--e.