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_15 -> u_3. q. u -> ~u_3. p_19 or q_15. w_3 -> u_3. p_19 -> w_3.
p_19 -> u_3 can be inferred via the transitivity rule.