What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall y: U_3(y) <-> Q(y). exists y: S_4(y) -> U_3(y). forall y: Q(y) -> S_4(y).
exists y: Q(y) -> U_3(y). forall y: U_3(y) -> Q(y). forall y: Q(y) -> U_3(y).