Translate the following inference to logic notation: For all x, x_8 will drive a car if and only if x_8 is a sailor. For all x, x_8 is a sailor if and only if x_8 will drive a car. Therefore for all x, x_8 will drive a car if and only if x_8 is a sailor.
forall x: P(x) <-> Q(x). forall x: Q(x) <-> P(x). Therefore forall x: P(x) <-> Q(x).