1248, Ye Li, a mathematician in the Jin Dynasty, systematically introduced the establishment of quadratic equation in his works "Measuring the Round Sea Mirror" and "An Ancient Analysis", while Zhu Shijie, a mathematician in the Yuan Dynasty,

According to historical records, a number of works on magic appeared in the Jin and Yuan Dynasties, such as Jiangzhou's Yi Gu Yan Duan, Li Wenyi's Zhao Dan, Shi Xindu's Zhongjing, and Liu Rukai's Entering Discipline and Unlocking. (Zu Ti's preface to Zhu Shijie's Four Jade Juanjian), but it has been lost. However, in the later works of Ye Li and Zhu Shijie, the art of Heaven was clearly expounded.

Related introduction:

The emergence of celestial sphere provides a unified method for equations, and its steps are much more advanced than the algebra of Arab mathematicians. In Europe, this was not achieved until16th century. In addition, the method of addition, multiplication and division, which was founded in the Song Dynasty, simplified the operation process of solving the positive root of mathematical high-order equations. Therefore, in this period, there were simple and clear methods and procedures for solving equations, and China's classical algebra developed to a relatively complete stage.

Moreover, after the celestial sphere technology, mathematicians quickly extended this method to higher-order multivariate equations. For example, Li Dezai's Collection of Talented Persons with Two Instruments has the duality of heaven and earth, Liu Dajian's Gankun Kuobao has the ternary of heaven, earth and people, and finally Zhu Shijie founded the Quaternary Technique.