Translate the following inference to logic notation: For all x, if x_5 were an astronaut, then x_5 is a sailor. For all x, x_5 will work if and only if x_5 is a soldier. For all x, if x_5 were a sailor, then x_5 is a soldier. For all x, x_5 is an astronaut or x_5 will work. Therefore for all x, x_5 is a soldier.
forall x: P(x) -> Q(x). forall x: R(x) <-> S(x). forall x: Q(x) -> S(x). forall x: P(x) or R(x). Therefore forall x: S(x).