question: Did M3 and M4 star a film editor influenced by M1 and influenced by M2
query: SELECT count(*) WHERE {
  ?x0 a ns:film.editor .
  ?x0 ns:influence.influence_node.influenced_by M1 .
  ?x0 ns:influence.influence_node.influenced_by M2 .
  M3 ns:film.film.starring/ns:film.performance.actor ?x0 .
  M4 ns:film.film.starring/ns:film.performance.actor ?x0
  }