Translate the following inference to logic notation: There is at least one x for which if y_1 were a lawyer, then y_1 is not an artist. For all x, y_1 is a lawyer if and only if y_1 is a writer. For all x, y_1 is an artist. Therefore there is at least one x for which y_1 is not a writer.
exists x: P(x) -> ~Q(x). forall x: P(x) <-> R(x). forall x: Q(x). Therefore exists x: ~R(x).