Translate the following inference to logic notation: For all x, x_7 is a soldier if and only if x_7 will work. For all x, x_7 will play tennis. For all x, x_7 is not a soldier. For all x, x_7 will work or x_7 is a janitor. Therefore for all x, x_7 will play tennis and x_7 is a janitor.
forall x: P(x) <-> Q(x). forall x: R(x). forall x: ~P(x). forall x: Q(x) or S(x). Therefore forall x: R(x) and S(x).