Translate the following inference to logic notation: For all x, if x_14 were a cashier, then x_14 is climbing a mountain. For all x, if x_14 climbs a mountain, then x_14 is a cashier. For all x, x_14 will climb a mountain if and only if x_14 is a taxi driver. There is at least one x for which if x_14 were a cashier, then x_14 is taking a plane. Therefore there is at least one x for which if x_14 were a taxi driver, then x_14 is taking a plane.
forall x: P(x) -> Q(x). forall x: Q(x) -> P(x). forall x: Q(x) <-> R(x). exists x: P(x) -> S(x). Therefore exists x: R(x) -> S(x).