Translate the following inference to logic notation: There is at least one x for which if x_11 goes running, then x_11 is a taxi driver. For all x, x_11 will go running. For all x, if x_11 writes a letter, then x_11 is not listening to a song. For all x, if x_11 were a taxi driver, then x_11 is listening to a song. Therefore there is at least one x for which x_11 will not write a letter.
exists x: P(x) -> Q(x). forall x: P(x). forall x: R(x) -> ~S(x). forall x: Q(x) -> S(x). Therefore exists x: ~R(x).