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_9(a_8) -> t_2. P_9(a_8) -> u. t_2 -> u. forall x_9: P_9(x_9).
Q_9(a_8) -> u can be inferred via the transitivity rule.