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_3. s <-> p_3. ~t. t or q_4.
q_4 can be inferred via the disjunctive syllogism rule. ~p_3 and ~t can be inferred via the conjunction rule. ~t and ~p_3 can be inferred via the conjunction rule. s -> p_3 can be inferred via the biconditional elimination rule. p_3 -> s can be inferred via the biconditional elimination rule. ~s can be inferred via the biconditional elimination rule.