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: u_2. p_15 -> r. r -> w. q_15 -> r. p_15 or q_15.
p_15 -> w can be inferred via the transitivity rule. q_15 -> w can be inferred via the transitivity rule. r can be inferred via the disjunction elimination rule.