What film producer employed M1 , employed M2 and M3 , and employed M4 , M5 , and M6
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.producer .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M1 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M2 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M3 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M4 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M5 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M6
}