Were M2 and M3 employed by a company that M1 acquired
SELECT count(*) WHERE {
?x0 a ns:business.employer .
?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M1 .
M2 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0 .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0
}