Translate the following inference to logic notation: For all x, x_13 is an office clerk or x_13 will go running. For all x, if x_13 plays squash, then x_13 is cooking. For all x, x_13 will play squash if and only if x_13 will go running. There is at least one x for which if x_13 were an office clerk, then x_13 is playing squash. Therefore there is at least one x for which x_13 will cook.
forall x: P(x) or Q(x). forall x: R(x) -> S(x). forall x: R(x) <-> Q(x). exists x: P(x) -> R(x). Therefore exists x: S(x).