Translate the following inference to logic notation: There is at least one x for which if x_4 drives a car, then x_4 is playing squash. For all x, x_4 will drive a car or x_4 will not play squash. For all x, x_4 will not drive a car. Therefore there is at least one x for which x_4 will not play squash.
exists x: P(x) -> Q(x). forall x: P(x) or ~Q(x). forall x: ~P(x). Therefore exists x: ~Q(x).