What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall y: P_4(y) <-> P(y). forall y: P_4(y). exists y: W_2(y) -> P(y).
forall y: P_4(y) -> P(y). forall y: P(y) -> P_4(y).