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: q_8 -> t_4. t_4 -> u_3. ~t_1. t_1 <-> t_4. u_3 -> q_8.
q_8 -> u_3 can be inferred via the transitivity rule. t_4 -> q_8 can be inferred via the transitivity rule. u_3 -> t_4 can be inferred via the transitivity rule. t_1 -> t_4 can be inferred via the biconditional elimination rule. t_4 -> t_1 can be inferred via the biconditional elimination rule. ~t_4 can be inferred via the biconditional elimination rule.