jena-sdb/testing/Structure/struct-10.rq

PREFIX  xsd:    <http://www.w3.org/2001/XMLSchema#>
PREFIX  :       <http://example/>
PREFIX  ex:     <http://example/ns#>

# Optional var in RHS.

SELECT *
{
   { ?x :p ?z OPTIONAL { ?z :q1 ?w } }
   ?x :p ?w 
}