Who founded M1 and M2 , founded M3 and M4 , and founded a company
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:people.person .
?x0 ns:organization.organization_founder.organizations_founded ?x1 .
?x0 ns:organization.organization_founder.organizations_founded M1 .
?x0 ns:organization.organization_founder.organizations_founded M2 .
?x0 ns:organization.organization_founder.organizations_founded M3 .
?x0 ns:organization.organization_founder.organizations_founded M4 .
?x1 a ns:business.employer
}