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: exists x_2: S(x_2) <-> W(x_2). forall x_2: W(x_2) <-> S(x_2).
forall x_2: W(x_2) -> S(x_2) can be inferred via the universal biconditional elimination rule. exists x_2: S(x_2) -> W(x_2) can be inferred via the existential biconditional elimination rule. forall x_2: S(x_2) -> W(x_2) can be inferred via the universal biconditional elimination rule. exists x_2: W(x_2) -> S(x_2) can be inferred via the existential biconditional elimination rule.