Translate the following inference to logic notation: For all x, x_11 is an astronaut if and only if x_11 is an office clerk. For all x, if x_11 plays squash, then x_11 is an office clerk. For all x, if x_11 were an astronaut, then x_11 is playing squash. Therefore if Mary were an astronaut, then Mary is playing squash.
forall x: P(x) <-> Q(x). forall x: R(x) -> Q(x). forall x: P(x) -> R(x). Therefore P(a) -> R(a).