Translate the following inference to logic notation: For all x, x_6 will not take a plane. For all x, if x_6 climbs a mountain, then x_6 is taking a plane. There is at least one x for which if x_6 takes a plane, then x_6 is climbing a mountain. Therefore there is at least one x for which x_6 will not climb a mountain.
forall x: ~P(x). forall x: Q(x) -> P(x). exists x: P(x) -> Q(x). Therefore exists x: ~Q(x).