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: q_1 -> u. ~s_3. t_3 -> s_3. u -> t_3.
~t_3 can be inferred via the modus tollens rule. q_1 -> t_3 can be inferred via the transitivity rule. u -> s_3 can be inferred via the transitivity rule.