Was M4 a company whose Canadian employee was employed by M0 , M1 , and M2
SELECT count(*) WHERE {
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M0 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
?x0 ns:people.person.nationality ns:m.0d060g .
M4 a ns:business.employer .
M4 ns:business.employer.employees/ns:business.employment_tenure.person ?x0
}