Based on the ancient astronomical calendar and other related knowledge, Liuyi conducts operations, deductions and judgments. It is a great achievement in the collection of Taiji, Yinyang, Wuxing, Gossip, Ganzhi and Jiugong. Liuyi and Qimen, Taiyi is known as the three styles, of which Taiyi occupies the heavens, Qimenbu geography, six squats, and the heavens and the earth, and the personnel is the largest, so the Sixth is called the third. The four lessons and three passes are the predictive for