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: r -> q. q_2 or w. w -> r. q -> q_4. q_4 -> r_1. q_2 -> r_1.
r -> q_4 can be inferred via the transitivity rule. w -> q can be inferred via the transitivity rule. q -> r_1 can be inferred via the transitivity rule.