Translate the following inference to logic notation: There is at least one x for which if x_7 drives a car, then x_7 is climbing a mountain. For all x, if x_7 were a soldier, then x_7 is driving a car. For all x, if x_7 were a soldier, then x_7 is climbing a mountain. For all x, if x_7 climbs a mountain, then x_7 is a soldier. Therefore there is at least one x for which x_7 is a soldier if and only if x_7 will climb a mountain.
exists x: P(x) -> Q(x). forall x: R(x) -> P(x). forall x: R(x) -> Q(x). forall x: Q(x) -> R(x). Therefore exists x: R(x) <-> Q(x).