Translate the following inference to logic notation: There is at least one x for which if z_2 were a nurse, then z_2 is a musician. For all x, z_2 is a musician if and only if z_2 is a nurse. For all x, z_2 is not a nurse. Therefore there is at least one x for which z_2 is not a musician.
exists x: P(x) -> Q(x). forall x: Q(x) <-> P(x). forall x: ~P(x). Therefore exists x: ~Q(x).