Translate the following inference to logic notation: If it snows, then Joseph is drinking water. If Sarah were a lawyer, then David is writing a letter. David is writing a letter if and only if it is snowing. For all x, x will not drink water. If Joseph drinks water, then it is snowing. Therefore Sarah is not a lawyer.
p -> P(a). q -> r. r <-> p. forall x: ~P(x). P(a) -> p. Therefore ~q.