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 -> t_4. u_1 -> t. t_4 -> r_6. q -> u_1.
t -> r_6 can be inferred via the transitivity rule. u_1 -> t_4 can be inferred via the transitivity rule. q -> t can be inferred via the transitivity rule.