Translate the following inference to logic notation: John is not playing squash. For all x, if x_3 drinks water, then x_3 is playing squash. For all x, if x_3 plays squash, then x_3 is drinking water. Therefore John is not drinking water.
~P(a). forall x: Q(x) -> P(x). forall x: P(x) -> Q(x). Therefore ~Q(a).