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: ~t. p_3 -> t. p_4 -> q_8. t <-> p_4. q_8 -> p_3.
~p_3 can be inferred via the modus tollens rule. p_4 -> p_3 can be inferred via the transitivity rule. q_8 -> t can be inferred via the transitivity rule. t -> p_4 can be inferred via the biconditional elimination rule. p_4 -> t can be inferred via the biconditional elimination rule. ~p_4 can be inferred via the biconditional elimination rule.