What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_13: P_13(x_13) -> R(x_13). exists x_13: P_6(x_13) -> R(x_13). forall x_13: R(x_13) -> P_13(x_13). forall x_13: P_6(x_13) or ~P_13(x_13).
exists x_13: P_6(x_13) -> P_13(x_13). forall x_13: P_13(x_13) -> P_6(x_13). forall x_13: P_13(x_13) <-> R(x_13). forall x_13: R(x_13) <-> P_13(x_13).