What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? r_4 -> S_4(a_7). forall x: S_4(x) <-> P_3(x). P_3(a_7) or r_4.
forall x: S_4(x) -> P_3(x). forall x: P_3(x) -> S_4(x).