Translate the following inference to logic notation: For all x, if x were sad, then x is driving a car. For all x, x is not sad. There is at least one x for which if x drives a car, then x is sad. Therefore there is at least one x for which x will not drive a car.
forall x: P(x) -> Q(x). forall x: ~P(x). exists x: Q(x) -> P(x). Therefore exists x: ~Q(x).