Translate the following inference to logic notation: For all x, if x_9 were a taxi driver, then x_9 is playing squash. For all x, x_9 is a bartender if and only if x_9 will drink water. There is at least one x for which x_9 will drink water if and only if x_9 is a taxi driver. For all x, x_9 will not play squash. Therefore there is at least one x for which x_9 is not a bartender.
forall x: P(x) -> Q(x). forall x: R(x) <-> S(x). exists x: S(x) <-> P(x). forall x: ~Q(x). Therefore exists x: ~R(x).