Translate the following inference to logic notation: For all x, if y makes tea, then y is fast. For all x, y will make tea or y is not fast. For all x, if y were fast, then y is making tea. Therefore for all x, y is fast if and only if y will make tea.
forall x: P(x) -> Q(x). forall x: P(x) or ~Q(x). forall x: Q(x) -> P(x). Therefore forall x: Q(x) <-> P(x).