HCLSIG BioRDF Subgroup/QueryFederation/dbpedia inferencing

HCLSIG BioRDF Subgroup/QueryFederation/DBpedia Inferencing

For our use case, we are interested in Virtuoso's support for inferencing over the transitive closure of rdfs:subClassOf.

To retrieve just the classes in the hierarchy, use a query of the form (http://tinyurl.com/b8l3sh, only works on Virtuoso 6):

select ?x
from <http://dbpedia.org/resource/classes/yago#>
where {
         { select *
           where { ?x rdfs:subClassOf ?y . }
         }
         option (transitive,
                 t_distinct,
                 t_in (?x),
                 t_out (?y)
                 ) .
         filter (?y = <http://dbpedia.org/class/yago/Structure105225602>)
      }

To retrieve instances of classes in the hierarchy, use a query of the form (http://tinyurl.com/cvfzeu):

define input:inference 'http://dbpedia.org/resource/inference/rules/yago#'
PREFIX yago:<http://dbpedia.org/class/yago/>

SELECT DISTINCT ?receptor
from <http://dbpedia.org/resource/classes/yago#>
WHERE {
 ?receptor a yago:Receptor105608868 . }