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: ~p. p or t_2. t_2 -> q_1. q_1 -> r_1.
t_2 -> r_1 can be inferred via the transitivity rule. t_2 can be inferred via the disjunctive syllogism rule.