Translate the following inference to logic notation: For all x, if z_3 sleeps, then z_3 is a politician. David is not a politician. For all x, z_3 will sleep or z_3 is not a politician. Therefore David is not sleeping.
forall x: P(x) -> Q(x). ~Q(a). forall x: P(x) or ~Q(x). Therefore ~P(a).