Translate the following inference to logic notation: If Richard writes a letter, then David is driving a car. If John drinks water, then Richard is writing a letter. For all x, x_12 is a mechanic if and only if x_12 will drive a car. Therefore if John drinks water, then David is a mechanic.
p -> P(a). q -> p. forall x: Q(x) <-> P(x). Therefore q -> Q(a).