question: Was a film director that was influenced by M1 influenced by M2 and M3
query: SELECT count(*) WHERE {
  ?x0 a ns:film.director .
  ?x0 ns:influence.influence_node.influenced_by M1 .
  ?x0 ns:influence.influence_node.influenced_by M2 .
  ?x0 ns:influence.influence_node.influenced_by M3
  }