Was M1 a employer of M0 's sibling
SELECT count(*) WHERE {
?x0 ns:people.person.sibling_s/ns:people.sibling_relationship.sibling|ns:fictional_universe.fictional_character.siblings/ns:fictional_universe.sibling_relationship_of_fictional_characters.siblings M0 .
FILTER ( ?x0 != M0 ) .
M1 ns:business.employer.employees/ns:business.employment_tenure.person ?x0
}