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 x: Q(x) -> P_2(x). forall x: R(x) <-> Q(x). forall x: P_2(x) -> R(x).
forall x: Q(x) -> R(x) can be inferred via the universal transitivity rule. forall x: R(x) -> Q(x) can be inferred via the universal biconditional elimination rule. forall x: Q(x) -> R(x) can be inferred via the universal biconditional elimination rule.