What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_9: U_1(x_9) <-> W(x_9). forall x_9: W(x_9) -> ~P_9(x_9). P_9(a_9).
exists x: P_9(x). forall x_9: U_1(x_9) -> W(x_9). forall x_9: W(x_9) -> U_1(x_9).