What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? p_13 <-> S_21(a_21). ~R_21(a_21). forall x_21: R_21(x_21) <-> S_21(x_21). w_2 <-> p_13.
p_13 -> S_21(a_21). w_2 -> p_13. S_21(a_21) -> p_13. p_13 -> w_2. forall x_21: R_21(x_21) -> S_21(x_21). forall x_21: S_21(x_21) -> R_21(x_21).