What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? P_1(a_1). forall x_13: U(x_13) -> Q(x_13). forall x_13: S_2(x_13) -> Q(x_13). forall x_13: S_2(x_13) or U(x_13).
exists x: P_1(x). forall x_13: Q(x_13).