Translate the following inference to logic notation: William is rich if and only if James is a sailor. Michael is not playing tennis. For all x, if x_15 sleeps, then x_15 is rich. Michael is playing tennis if and only if James is a sailor. Therefore William is not sleeping.
P(a) <-> p. ~q. forall x: Q(x) -> P(x). q <-> p. Therefore ~Q(a).