Translate the following inference to logic notation: For all x, x_15 is a soldier if and only if x_15 will drink water. For all x, if x_15 drives a car, then x_15 is drinking water. There is at least one x for which x_15 will drive a car if and only if x_15 is a soldier. Therefore there is at least one x for which if x_15 drives a car, then x_15 is a soldier.
forall x: P(x) <-> Q(x). forall x: R(x) -> Q(x). exists x: R(x) <-> P(x). Therefore exists x: R(x) -> P(x).