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: forall y: U(y). ~w_3. r_2 <-> w_3.
r_2 -> w_3 can be inferred via the biconditional elimination rule. w_3 -> r_2 can be inferred via the biconditional elimination rule. ~r_2 can be inferred via the biconditional elimination rule.