Did M3 and M4 influence a person that M1 and M2 were executive produced by
SELECT count(*) WHERE {
?x0 a ns:people.person .
?x0 ns:film.producer.films_executive_produced M1 .
?x0 ns:film.producer.films_executive_produced M2 .
M3 ns:influence.influence_node.influenced ?x0 .
M4 ns:influence.influence_node.influenced ?x0
}