Translate the following inference to logic notation: For all x, if x_4 takes a plane, then x_4 is playing tennis. For all x, if x_4 plays tennis, then x_4 is listening to a song. For all x, if x_4 were a taxi driver, then x_4 is playing tennis. For all x, x_4 is a taxi driver or x_4 will take a plane. Therefore for all x, x_4 will listen to a song.
forall x: P(x) -> Q(x). forall x: Q(x) -> R(x). forall x: S(x) -> Q(x). forall x: S(x) or P(x). Therefore forall x: R(x).