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 -> r. p_2 <-> p. r -> p_2.
p -> p_2 can be inferred via the transitivity rule. p_2 -> p can be inferred via the biconditional elimination rule. p -> p_2 can be inferred via the biconditional elimination rule.