Translate the following inference to logic notation: For all x, z is a janitor if and only if z will play squash. There is at least one x for which z is a janitor or z will not play squash. Therefore there is at least one x for which if z were a janitor, then z is playing squash.
forall x: P(x) <-> Q(x). exists x: P(x) or ~Q(x). Therefore exists x: P(x) -> Q(x).