What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x: S(x) or W(x). forall x: ~W_4(x). forall x: W_4(x) <-> W_2(x). exists x: S(x) <-> W_2(x).
forall x: W_4(x) -> W_2(x). exists x: S(x) -> W_2(x). forall x: W_2(x) -> W_4(x). exists x: W_2(x) -> S(x). forall x: ~W_2(x).