Was a person whose employer was acquired by M0 and was acquired by M1 and M2 M3
SELECT count(*) WHERE {
?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M0 .
?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M1 .
?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M2 .
M3 a ns:people.person .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0
}