Translate the following inference to logic notation: For all x, x_13 will play tennis if and only if x_5 is a politician. For all x, if x_13 writes a letter, then x_5 is a politician. For all x, if x_5 were a politician, then x_5 is poor. For all x, x_13 will write a letter or x_13 will play tennis. Therefore Thomas is poor.
forall x: P(x) <-> Q(x). forall x: R(x) -> Q(x). forall x: Q(x) -> S(x). forall x: R(x) or P(x). Therefore S(a).