Translate the following inference to logic notation: There is at least one x for which if x_5 writes a letter, then x_5 is rich. For all x, if x_5 drinks water, then x_5 is rich. For all x, if x_5 were rich, then x_5 is drinking water. Therefore there is at least one x for which if x_5 writes a letter, then x_5 is drinking water.
exists x: P(x) -> Q(x). forall x: R(x) -> Q(x). forall x: Q(x) -> R(x). Therefore exists x: P(x) -> R(x).