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 -> ~s. s. p -> ~u_2. u_2.
~p_12 can be inferred via the modus tollens rule. ~p can be inferred via the modus tollens rule. s and u_2 can be inferred via the conjunction rule. u_2 and s can be inferred via the conjunction rule.