《汉书·志·律历志上》
三统合成一元，因此用元一乘以三的九次方形成法数，用三的十一次方作为实数。
三统合于一元，故因元一而九三之以为法，十一三之以为实。
The three unifications are combined into one Yuan, so the number of Yuan is formed by multiplying Yuan by the ninth power of three, and the real number is the eleventh power of three.