What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_8: P_8(x_8) <-> U_4(x_8). exists x_8: Q(x_8) -> U_4(x_8). forall x_8: ~P_8(x_8).
forall x_8: P_8(x_8) -> U_4(x_8). forall x_8: U_4(x_8) -> P_8(x_8). forall x_8: ~U_4(x_8).