What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall y: P(y) -> T(y). forall y: T(y) -> P(y). forall y: P(y) <-> P_3(y). exists y: ~P_3(y).
forall y: P(y) <-> T(y). forall y: T(y) <-> P(y). forall y: P(y) -> P_3(y). forall y: P_3(y) -> P(y). exists y: ~P(y).