The solution L ^ ^ cannot be simply of the form L ^ ^ = L ( x ^ ^ , p ^ ^ ) because it would imply the contractions i m [ L ( x ^ ^ , p ^ ^ ) , x ^ ^ ] = 0 = p ^ ^ and i [ L ( x ^ ^ , p ^ ^ ) , p ^ ^ ] = 0 = − − U ′ ( x ^ ^ ) . Therefore, we must utilize additional operators λ λ ^ ^ x and λ λ ^ ^ p obeying