(project (?first ?last ?homeTel)
    (order (?last)
      (filter (contains ?last "M")
        (join
          (leftjoin
            (table unit)
            (bgp (triple ?s <http://example.org/ab#homeTel> ?homeTel)))
          (bgp
            (triple ?s <http://example.org/ab#firstName> ?first)
            (triple ?s <http://example.org/ab#lastName> ?last)
          )))))