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_1. p_18 or q_18. p_1 or ~s_3. ~p_18.
q_18 can be inferred via the disjunctive syllogism rule. ~s_3 can be inferred via the disjunctive syllogism rule. ~p_1 and ~p_18 can be inferred via the conjunction rule. ~p_18 and ~p_1 can be inferred via the conjunction rule. s_3 -> p_1 can be inferred via the rewriting rule.