question: Was M2 a film director that was influenced by a film producer , was influenced by M4 , and influenced a person
query: SELECT count(*) WHERE {
  ?x0 a ns:people.person .
  ?x1 a ns:film.producer .
  M2 a ns:film.director .
  M2 ns:influence.influence_node.influenced ?x0 .
  M2 ns:influence.influence_node.influenced_by ?x1 .
  M2 ns:influence.influence_node.influenced_by M4
  }