Translate the following inference to logic notation: For all x, x_13 is a janitor if and only if x_13 is an artist. For all x, x_13 will cook. For all x, if x_13 were a janitor, then x_13 is a nurse. For all x, x_13 is a janitor or x_13 will not cook. Therefore for all x, x_13 is a nurse.
forall x: P(x) <-> Q(x). forall x: R(x). forall x: P(x) -> S(x). forall x: P(x) or ~R(x). Therefore forall x: S(x).