Did M1 employ a person and employ M2 , M3 , and M4
SELECT count(*) WHERE {
?x0 a ns:people.person .
M1 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
M1 ns:business.employer.employees/ns:business.employment_tenure.person M2 .
M1 ns:business.employer.employees/ns:business.employment_tenure.person M3 .
M1 ns:business.employer.employees/ns:business.employment_tenure.person M4
}