question: Was a person influenced by a character , influenced by M1 , influenced by M2 , and influenced by M3
query: SELECT count(*) WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:influence.influence_node.influenced_by ?x1 .
  ?x0 ns:influence.influence_node.influenced_by M1 .
  ?x0 ns:influence.influence_node.influenced_by M2 .
  ?x0 ns:influence.influence_node.influenced_by M3 .
  ?x1 a ns:fictional_universe.fictional_character
  }