Translate the following inference to logic notation: For all x, x_5 is a sailor if and only if x_5 is a doctor. For all x, if x_5 were a sailor, then x_5 is playing tennis. For all x, x_5 is not a doctor. For all x, if x_5 plays tennis, then x_5 is a sailor. Therefore for all x, x_5 will not play tennis.
forall x: P(x) <-> Q(x). forall x: P(x) -> R(x). forall x: ~Q(x). forall x: R(x) -> P(x). Therefore forall x: ~R(x).