Translate the following inference to logic notation: For all x, if x_15 drives a car, then x_15 is listening to a song. For all x, if x_15 were sad, then x_15 is not a mechanic. For all x, if x_15 were a police officer, then x_15 is a mechanic. For all x, x_15 will drive a car. There is at least one x for which if x_15 listens to a song, then x_15 is a police officer. Therefore there is at least one x for which x_15 is not sad.
forall x: P(x) -> Q(x). forall x: R(x) -> ~S(x). forall x: T(x) -> S(x). forall x: P(x). exists x: Q(x) -> T(x). Therefore exists x: ~R(x).