Translate the following inference to logic notation: For all x, x_5 is an office clerk. For all x, x_5 is a sailor if and only if x_5 will drink water. There is at least one x for which if x_5 were an office clerk, then x_5 is drinking water. Therefore there is at least one x for which x_5 will drink water.
forall x: P(x). forall x: Q(x) <-> R(x). exists x: P(x) -> R(x). Therefore exists x: R(x).