Translate the following inference to logic notation: For all x, if x_5 were a cashier, then x_5 is driving a car. For all x, if x_5 plays squash, then x_5 is a cashier. For all x, if x_5 drives a car, then x_5 is making tea. There is at least one x for which if x_5 makes tea, then x_5 is playing squash. Therefore there is at least one x for which x_5 is a cashier if and only if x_5 will make tea.
forall x: P(x) -> Q(x). forall x: R(x) -> P(x). forall x: Q(x) -> S(x). exists x: S(x) -> R(x). Therefore exists x: P(x) <-> S(x).