Translate the following inference to logic notation: For all x, x is sad if and only if x will drive a car. There is at least one x for which if x drives a car, then x is a janitor. For all x, if x drinks water, then x is sad. Therefore there is at least one x for which if x drinks water, then x is a janitor.
forall x: P(x) <-> Q(x). exists x: Q(x) -> R(x). forall x: S(x) -> P(x). Therefore exists x: S(x) -> R(x).