question: Was a British film producer influenced by M1 and influenced by M2
query: SELECT count(*) WHERE {
  ?x0 a ns:film.producer .
  ?x0 ns:influence.influence_node.influenced_by M1 .
  ?x0 ns:influence.influence_node.influenced_by M2 .
  ?x0 ns:people.person.nationality ns:m.07ssc
  }