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_18: Q_11(x_18) -> Q_2(x_18). forall x_18: Q_4(x_18) -> W(x_18). exists x_18: P_11(x_18) -> Q_2(x_18). forall x_18: R(x_18) or Q_4(x_18). forall x_18: R(x_18) -> W(x_18). forall x_18: P_11(x_18) or Q_11(x_18). forall x_18: W(x_18) -> R(x_18).
forall x_18: Q_4(x_18) -> R(x_18) can be inferred via the universal transitivity rule. forall x_18: W(x_18) can be inferred via the universal disjunction elimination rule. exists x_18: Q_2(x_18) can be inferred via the existential disjunction elimination rule. forall x_18: R(x_18) <-> W(x_18) can be inferred via the universal biconditional introduction rule. forall x_18: W(x_18) <-> R(x_18) can be inferred via the universal biconditional introduction rule.