Were M1 and M2 influenced by a person and influenced by a person
SELECT count(*) WHERE {
?x0 a ns:people.person .
?x1 a ns:people.person .
M1 ns:influence.influence_node.influenced_by ?x0 .
M1 ns:influence.influence_node.influenced_by ?x1 .
M2 ns:influence.influence_node.influenced_by ?x0 .
M2 ns:influence.influence_node.influenced_by ?x1
}