Translate the following inference to logic notation: There is at least one x for which if y were a taxi driver, then y is sleeping. For all x, y is not a taxi driver. For all x, y is a taxi driver or y will not sleep. Therefore there is at least one x for which y will not sleep.
exists x: P(x) -> Q(x). forall x: ~P(x). forall x: P(x) or ~Q(x). Therefore exists x: ~Q(x).