Translate the following inference to logic notation: For all x, if z drives a car, then z is sad. For all x, if z were a poet, then z is driving a car. For all x, if z drives a car, then z is a poet. There is at least one x for which z is not a poet. For all x, if z were sad, then z is driving a car. Therefore there is at least one x for which z is not sad.
forall x: P(x) -> Q(x). forall x: R(x) -> P(x). forall x: P(x) -> R(x). exists x: ~R(x). forall x: Q(x) -> P(x). Therefore exists x: ~Q(x).