Translate the following inference to logic notation: There is at least one x for which if x_4 writes a letter, then x_4 is playing squash. For all x, x_4 will drink water. For all x, x_4 will write a letter. Therefore there is at least one x for which x_4 will drink water.
exists x: P(x) -> Q(x). forall x: R(x). forall x: P(x). Therefore exists x: R(x).