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