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: t_1 -> t_3. t_1 <-> t_3.
t_1 -> t_3 can be inferred via the biconditional elimination rule. t_3 -> t_1 can be inferred via the biconditional elimination rule.