Translate the following inference to logic notation: For all x, x_6 will not write a letter. There is at least one x for which if x_6 goes running, then x_6 is taking a plane. For all x, x_6 will write a letter or x_6 will not take a plane. Therefore there is at least one x for which x_6 will not go running.
forall x: ~P(x). exists x: Q(x) -> R(x). forall x: P(x) or ~R(x). Therefore exists x: ~Q(x).