Du's full name is "The Classic of the Top Grade of Emperor Tai Shang's Lingbao Infinite Man". Known as the head of the group classics, the Sect of all laws, and the source of all legal circles. It is the core classic of Fu You Lingbao School of Sanshan Taoism, a orthodox school.
Du Zhun is the most important of Chen Jingyuan's Four Notes in Yuan Dynasty. Among these four interpretations, harmony is the most wonderful and mysterious one. Xue Youqi's philosophical thought is obviously more primitive and rough than Cheng's. Cheng's annotation is a supplement to the annotation, and the idea of Du in Cheng's annotation is the closest.