Translate the following inference to logic notation: There is at least one x for which x_9 is sad if and only if x_9 will make tea. For all x, x_9 will make tea or x_9 is a politician. For all x, x_9 will not drink water. For all x, if x_9 were sad, then x_9 is drinking water. Therefore there is at least one x for which x_9 is a politician.
exists x: P(x) <-> Q(x). forall x: Q(x) or R(x). forall x: ~S(x). forall x: P(x) -> S(x). Therefore exists x: R(x).