Translate the following inference to logic notation: For all x, x_11 is a bartender if and only if x_11 is a janitor. For all x, if x_11 were a janitor, then x_11 is a nurse. There is at least one x for which x_11 is not a nurse. Therefore there is at least one x for which x_11 is not a bartender.
forall x: P(x) <-> Q(x). forall x: Q(x) -> R(x). exists x: ~R(x). Therefore exists x: ~P(x).