Who influenced and was influenced by a employee of M1 , M2 , M3 , and M4
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:people.person .
?x0 ns:influence.influence_node.influenced ?x1 .
?x0 ns:influence.influence_node.influenced_by ?x1 .
?x1 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
?x1 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
?x1 ns:people.person.employment_history/ns:business.employment_tenure.company M3 .
?x1 ns:people.person.employment_history/ns:business.employment_tenure.company M4
}