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 or r_2. u_2 or u. p_7 -> t_4. ~u_2 or p_7. t_4 -> r_7. r_2 -> r_7.
p_7 -> r_7 can be inferred via the transitivity rule. u or p_7 can be inferred via the resolution rule.