Translate the following inference to logic notation: For all x, z is not a scientist. For all x, z will read a book if and only if z is a scientist. For all x, z will read a book if and only if z is a janitor. Therefore for all x, z is not a janitor.
forall x: ~P(x). forall x: Q(x) <-> P(x). forall x: Q(x) <-> R(x). Therefore forall x: ~R(x).