Translate the following inference to logic notation: For all x, if x_15 writes a letter, then x_15 is playing tennis. For all x, x_15 will write a letter if and only if x_15 is a scientist. For all x, x_15 is a scientist or x_15 is rich. For all x, if x_15 were rich, then x_15 is a bartender. For all x, x_15 will play tennis if and only if x_15 is a bartender. Therefore for all x, x_15 is a bartender.
forall x: P(x) -> Q(x). forall x: P(x) <-> R(x). forall x: R(x) or S(x). forall x: S(x) -> T(x). forall x: Q(x) <-> T(x). Therefore forall x: T(x).