Translate the following inference to logic notation: For all x, y will take a plane or y is not poor. For all x, y is poor if and only if y will take a plane. Therefore for all x, y will take a plane if and only if y is poor.
forall x: P(x) or ~Q(x). forall x: Q(x) <-> P(x). Therefore forall x: P(x) <-> Q(x).