Translate the following inference to logic notation: For all x, if z were an astronaut, then z is an artist. For all x, z will make tea or z will drink water. There is at least one x for which z will drink water if and only if z is an artist. For all x, if z makes tea, then z is an astronaut. Therefore there is at least one x for which z is an artist.
forall x: P(x) -> Q(x). forall x: R(x) or S(x). exists x: S(x) <-> Q(x). forall x: R(x) -> P(x). Therefore exists x: Q(x).