What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_15: S_3(x_15) -> S_15(x_15). w_4 -> S_3(a_15). S_15(a_15) <-> q_9. w_4 or q_9.
S_15(a_15) -> q_9. q_9 -> S_15(a_15).