Translate the following inference to logic notation: For all x, y_3 will cook if and only if y_3 will play squash. There is at least one x for which if y_3 were an astronaut, then y_3 is playing squash. For all x, y_3 will not cook. For all x, if y_3 plays squash, then y_3 is an astronaut. Therefore there is at least one x for which y_3 is not an astronaut.
forall x: P(x) <-> Q(x). exists x: R(x) -> Q(x). forall x: ~P(x). forall x: Q(x) -> R(x). Therefore exists x: ~R(x).