What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_1: T_4(x_1) -> P(x_1). forall x_1: P(x_1) -> T_4(x_1). P(a) -> T_4(a).
forall x_1: T_4(x_1) <-> P(x_1). forall x_1: P(x_1) <-> T_4(x_1).