Translate the following inference to logic notation: For all x, if x_7 writes a letter, then x_7 is poor. For all x, x_7 will write a letter if and only if x_7 is poor. Therefore if Patricia writes a letter, then Patricia is poor.
forall x: P(x) -> Q(x). forall x: P(x) <-> Q(x). Therefore P(a) -> Q(a).