What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? s -> q. ~r_1. p_8 <-> r_1. q -> p_8. p_8 -> s.
s -> p_8. q -> s. p_8 -> q. p_8 -> r_1. r_1 -> p_8. ~p_8.