Ye Li is the development of Tianyuan, a mathematician in Jin Dynasty.

Astrology is a general method of using unknown equations, which is basically consistent with the method of equations in modern algebra. In ancient mathematics, equation and solution are two important interrelated problems.

Before the Song Dynasty, it was difficult for mathematicians to list an equation. For example, in the Tang Dynasty, Wang Xiaotong used geometric methods to formulate cubic equations, which often required superb mathematical skills, complicated derivation and a large number of written explanations.

With the development of multiplication and division founded in Song Dynasty, a perfect method of solving equations appeared, which directly promoted the research of equation methods, and then produced another outstanding creation of China's mathematics-Tianshu.

Impact:

Tianyuan Book is not Ye Li's original creation, but it has sprouted in northern China since the Jin Dynasty. According to Zu Ti's Preface to Four Jade Mirrors, there are at least Jiangzhou, Shi Xindao, Liu, Li Dezai, etc. Before Ye Li, but without mentioning Ye Li. Besides Ye Li, other early works of Tianyuan Art have also been lost.

1303, Zhu Shijie's "Four Yuan Jade Mirror" came out, in which the art of heaven was expanded to a "four yuan" including Tianyuan, Geo-yuan, Man-yuan and Matter-yuan, that is, the solution of four yuan higher order equations, which developed the art of heaven to a new height.