Translate the following inference to logic notation: For all x, if y were a cashier, then y is a police officer. For all x, if y were a police officer, then y is a cashier. There is at least one x for which if y plays squash, then y is a police officer. For all x, if y were a cashier, then y is a writer. Therefore there is at least one x for which if y plays squash, then y is a writer.
forall x: P(x) -> Q(x). forall x: Q(x) -> P(x). exists x: R(x) -> Q(x). forall x: P(x) -> S(x). Therefore exists x: R(x) -> S(x).