Translate the following inference to logic notation: For all x, x_5 will make tea. For all x, x_5 is a doctor if and only if x_5 will take a plane. For all x, if x_5 makes tea, then x_5 is taking a plane. Therefore for all x, x_5 is a doctor.
forall x: P(x). forall x: Q(x) <-> R(x). forall x: P(x) -> R(x). Therefore forall x: Q(x).