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_7: Q(x_7) <-> R(x_7). forall x_7: R_4(x_7) -> Q_1(x_7). forall x_7: Q_1(x_7) -> R(x_7). forall x_7: Q(x_7) or R_4(x_7).
forall x_7: R_4(x_7) -> R(x_7) can be inferred via the universal transitivity rule. forall x_7: Q(x_7) -> R(x_7) can be inferred via the universal biconditional elimination rule. forall x_7: R(x_7) -> Q(x_7) can be inferred via the universal biconditional elimination rule.