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: p_12 -> ~q_2. t or u_3. ~t. q_2.
~p_12 can be inferred via the modus tollens rule. u_3 can be inferred via the disjunctive syllogism rule. ~t and q_2 can be inferred via the conjunction rule. q_2 and ~t can be inferred via the conjunction rule.