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_8 <-> r_2. r_2 -> ~t. t.
~r_2 can be inferred via the modus tollens rule. p_8 -> r_2 can be inferred via the biconditional elimination rule. r_2 -> p_8 can be inferred via the biconditional elimination rule.