jena-arq/testing/ARQ/Syntax/Syntax-SPARQL_10_1/syntax-struct-14.rq

# Two elements in the group
PREFIX :  <http://example.org/ns#>
SELECT *
{ :p :q :r  OPTIONAL { :a :b :c } 
  :p :q :r  OPTIONAL { :a :b :c } 
}