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. q_12 -> t_3. s_4 or q_12. p_6 <-> t_3.
q_12 can be inferred via the disjunctive syllogism rule. p_6 -> t_3 can be inferred via the biconditional elimination rule. t_3 -> p_6 can be inferred via the biconditional elimination rule.