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: ~w. q_8 -> w. u -> q_8. w -> u.
~q_8 can be inferred via the modus tollens rule. q_8 -> u can be inferred via the transitivity rule. u -> w can be inferred via the transitivity rule. w -> q_8 can be inferred via the transitivity rule.