What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? exists y: P(y) or ~Q_4(y). forall y: P(y) <-> Q_4(y).
exists y: Q_4(y) -> P(y). forall y: P(y) -> Q_4(y). forall y: Q_4(y) -> P(y).