question: Was a person 's employer founded by M0 and M1 and founded by M2 and M3
query: SELECT count(*) WHERE {
  ?x0 ns:business.employer.employees/ns:business.employment_tenure.person ?x1 .
  ?x0 ns:organization.organization.founders M0 .
  ?x0 ns:organization.organization.founders M1 .
  ?x0 ns:organization.organization.founders M2 .
  ?x0 ns:organization.organization.founders M3 .
  ?x1 a ns:people.person
  }