Translate the following inference to logic notation: For all x, z will play squash or z will write a letter. There is at least one x for which if z writes a letter, then z is a taxi driver. For all x, if z plays squash, then z is a taxi driver. For all x, z will go running. Therefore there is at least one x for which z is a taxi driver.
forall x: P(x) or Q(x). exists x: Q(x) -> R(x). forall x: P(x) -> R(x). forall x: S(x). Therefore exists x: R(x).