Translate the following inference to logic notation: Elisabeth is making tea if and only if Elisabeth is cooking. If Elisabeth cooks, then Elisabeth is taking a plane. For all x, if x_17 takes a plane, then x_17 is making tea. Therefore if Elisabeth cooks, then Elisabeth is making tea.
P(a) <-> p. p -> Q(a). forall x: Q(x) -> P(x). Therefore p -> P(a).