Translate the following inference to logic notation: For all x, x_21 is a writer if and only if x_21 is a nurse. For all x, if x_21 were an office clerk, then x_21 is a writer. For all x, if x_21 writes a letter, then x_21 is a writer. For all x, x_21 will write a letter or x_21 is an office clerk. Therefore Linda is a nurse or it is raining.
forall x: P(x) <-> Q(x). forall x: R(x) -> P(x). forall x: S(x) -> P(x). forall x: S(x) or R(x). Therefore Q(a) or p.