Translate the following inference to logic notation: It is cloudy if and only if Susan is listening to a song. For all x, x_3 is a taxi driver if and only if x_3 will read a book. If it is cloudy, then Mary is reading a book. Mary is not a taxi driver. Therefore Susan is not listening to a song.
p <-> q. forall x: P(x) <-> Q(x). p -> Q(a). ~P(a). Therefore ~q.