What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_13: S_4(x_13) -> U_3(x_13). forall x_13: U_3(x_13) -> S_4(x_13). forall x_13: U_3(x_13) -> P_9(x_13). forall x_13: ~Q_9(x_13). forall x_13: P_9(x_13) -> Q_9(x_13).
forall x_13: ~P_9(x_13). forall x_13: S_4(x_13) -> P_9(x_13). forall x_13: U_3(x_13) -> Q_9(x_13). forall x_13: S_4(x_13) <-> U_3(x_13). forall x_13: U_3(x_13) <-> S_4(x_13).