What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: s -> q. q -> q_8. q_8 -> s. ~s.
~q_8 can be inferred via the modus tollens rule. s -> q_8 can be inferred via the transitivity rule. q -> s can be inferred via the transitivity rule. q_8 -> q can be inferred via the transitivity rule.