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: ~s_4. r. s_4 or ~q.
~q can be inferred via the disjunctive syllogism rule. ~s_4 and r can be inferred via the conjunction rule. r and ~s_4 can be inferred via the conjunction rule. q -> s_4 can be inferred via the rewriting rule.