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_5: U(x_5) -> ~R(x_5). forall x_5: R(x_5). forall x_5: W(x_5) -> U(x_5). forall x_5: U(x_5) -> W(x_5).
forall x_5: ~U(x_5) can be inferred via the universal modus tollens rule. forall x_5: W(x_5) <-> U(x_5) can be inferred via the universal biconditional introduction rule. forall x_5: U(x_5) <-> W(x_5) can be inferred via the universal biconditional introduction rule.