High Quality Content by WIKIPEDIA articles! Tian yuan shu is a Chinese system of algebra for polynomial equations created in the 13th century. It is first known from the writing of Li Zhi (Li Ye), though it was created earlier. The mathematical culture in which it was created was lost due to war and general suspiciousness during the Ming dynasty of knowledge from the (Mongolian) Yuan dynasty. The writings of Li Zhi, Qin Jiushao, Zhu Shijie and others could no longer be fully understood, until the... Mehr