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: r -> q_3. r_3 -> r. q_3 -> r_3. ~r_3.
~q_3 can be inferred via the modus tollens rule. r -> r_3 can be inferred via the transitivity rule. r_3 -> q_3 can be inferred via the transitivity rule. q_3 -> r can be inferred via the transitivity rule.