Translate the following inference to logic notation: It is overcast if and only if Susan is a poet. If it is cloudy, then David is a cashier. If it snows, then David is a cashier. It is snowing or it is cloudy. Susan is not a poet. Therefore it is not overcast and David is a cashier.
p <-> q. r -> s. t -> s. t or r. ~q. Therefore ~p and s.