Translate the following inference to logic notation: For all x, x_6 is not a sailor or x_6 is an office clerk. For all x, x_6 is a sailor or x_6 is an astronaut. For all x, if x_6 were an astronaut, then x_6 is playing squash. For all x, x_6 will play squash if and only if x_6 is an office clerk. Therefore for all x, x_6 will play squash.
forall x: ~P(x) or Q(x). forall x: P(x) or R(x). forall x: R(x) -> S(x). forall x: S(x) <-> Q(x). Therefore forall x: S(x).