Translate the following inference to logic notation: For all x, y will drive a car or y will sleep. For all x, if y works, then y is sleeping. For all x, y will work if and only if y will drive a car. For all x, if y sleeps, then y is working. Therefore Barbara is working.
forall x: P(x) or Q(x). forall x: R(x) -> Q(x). forall x: R(x) <-> P(x). forall x: Q(x) -> R(x). Therefore R(a).