- From: Ivan Herman <ivan@w3.org>
- Date: Mon, 27 Jul 2009 13:05:20 +0200
- To: Axel Rauschmayer <axel@rauschma.de>
- CC: public-lod@w3.org
- Message-ID: <4A6D89F0.7090400@w3.org>
Axel Rauschmayer wrote: >> You were asking about description logic programming; well, OWL 2 RL: >> >> http://www.w3.org/TR/owl2-profiles/#OWL_2_RL >> >> is exactly that: it is a manifestation of DLP. It has a Direct Semantics >> 'side', compatible with OWL 2 DL, and a rule based 'side', described by >> the rule set: >> >> http://www.w3.org/TR/owl2-profiles/#Reasoning_in_OWL_2_RL_and_RDF_Graphs_using_Rules >> >> >> This rule set can be used for a forward or backward chaining approach >> (or a combination thereof) that you describe. I have heard rumours >> and/or statements on implementations coming up from various vendors. I >> have, actually, a purely proof-of-concept-stupid-simple implementation >> doing brute force forward chaining: >> >> http://www.ivan-herman.net/Misc/2008/owlrl/ >> >> Just to show what happens. And I am sure other implementations will come >> to the fore that I do not yet about. > > > Cool stuff. How would backward chaining work? Would it be invoked via > SPARQL? Is listing all properties of a given resource still possible? > At this moment, your guess is as good as mine:-) We will have to see how implementers will come up with solution. _Conceptually_ one could say that the SPARQL query is done on the deductive closure (via OWL RL) of the data set. But taking it literally (ie, expanding the graph with, say, forward chaining, and making the query on top of it) is probably not efficient, so I expect implementers coming up with cool tricks:-) Ivan > Axel > -- Ivan Herman, W3C Semantic Web Activity Lead Home: http://www.w3.org/People/Ivan/ mobile: +31-641044153 PGP Key: http://www.ivan-herman.net/pgpkey.html FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Monday, 27 July 2009 11:05:55 UTC