Translate the following inference to logic notation: For all x, y_4 will drive a car if and only if y_4 will climb a mountain. There is at least one x for which if y_4 makes tea, then y_4 is driving a car. Therefore there is at least one x for which if y_4 makes tea, then y_4 is climbing a mountain.
forall x: P(x) <-> Q(x). exists x: R(x) -> P(x). Therefore exists x: R(x) -> Q(x).