Translate the following inference to logic notation: For all x, z_1 will make tea if and only if z_1 will cook. For all x, z_1 will make tea or z_1 will work. For all x, if z_1 works, then z_1 is cooking. For all x, if z_1 cooks, then z_1 is working. Therefore for all x, z_1 will cook.
forall x: P(x) <-> Q(x). forall x: P(x) or R(x). forall x: R(x) -> Q(x). forall x: Q(x) -> R(x). Therefore forall x: Q(x).