Translate the following inference to logic notation: For all x, x_9 will drive a car if and only if x_9 is happy. For all x, if x_9 were curious, then x_9 is a cashier. For all x, x_9 is not a cashier. There is at least one x for which if x_9 drives a car, then x_9 is curious. Therefore there is at least one x for which x_9 is not happy.
forall x: P(x) <-> Q(x). forall x: R(x) -> S(x). forall x: ~S(x). exists x: P(x) -> R(x). Therefore exists x: ~Q(x).