Translate the following inference to logic notation: For all x, if x_13 were a writer, then x_13 is playing tennis. For all x, x_13 will play tennis if and only if x_13 is a musician. For all x, x_13 is a musician or x_13 is a writer. For all x, if x_13 plays tennis, then x_13 is a writer. Therefore Linda is playing tennis.
forall x: P(x) -> Q(x). forall x: Q(x) <-> R(x). forall x: R(x) or P(x). forall x: Q(x) -> P(x). Therefore Q(a).