What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_13: R_4(x_13) -> U(x_13). forall x_13: U(x_13) <-> Q_12(x_13). exists x_13: ~Q_12(x_13). forall x_13: U(x_13) -> R_4(x_13).
forall x_13: R_4(x_13) <-> U(x_13). forall x_13: U(x_13) <-> R_4(x_13). forall x_13: U(x_13) -> Q_12(x_13). forall x_13: Q_12(x_13) -> U(x_13). exists x_13: ~U(x_13).