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: u -> t. ~w_2. u or s_2. w_2 or q_22. s_2 -> t. r -> ~q_22.
q_22 can be inferred via the disjunctive syllogism rule. t can be inferred via the disjunction elimination rule.