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_6 -> p. p -> w_3. w_3 -> q_4. q_4 -> r_6.
r_6 -> w_3 can be inferred via the transitivity rule. p -> q_4 can be inferred via the transitivity rule. w_3 -> r_6 can be inferred via the transitivity rule. q_4 -> p can be inferred via the transitivity rule.