Translate the following inference to logic notation: There is at least one x for which if x_3 drives a car, then x_3 is a bartender. For all x, x_3 is a bartender if and only if x_3 will drive a car. Therefore there is at least one x for which x_3 will drive a car if and only if x_3 is a bartender.
exists x: P(x) -> Q(x). forall x: Q(x) <-> P(x). Therefore exists x: P(x) <-> Q(x).