Translate the following inference to logic notation: There is at least one x for which y is a nurse or y will not make tea. For all x, y will make tea if and only if y is a nurse. Therefore there is at least one x for which y is a nurse if and only if y will make tea.
exists x: P(x) or ~Q(x). forall x: Q(x) <-> P(x). Therefore exists x: P(x) <-> Q(x).