There are forty-four lines in Le Yi Lun, and Chu Suiliang's Bibliography of Jin Xizhi ranks first. Liang Tao Hongjing said: "The Right Army has several famous monuments: Huang Tingjing, Bei Lun." The original is long gone. I said that the original was thrown into the kitchen fire for the old woman in Xianyang during the war; It is said that all the right army books collected by Emperor Taizong of Tang Dynasty are authentic, but this post only contains stone carvings. There are many kinds of existing printed editions, among which the Secret Pavilion edition and Yuezhou Shishi edition are the best. This post, like Huang Tingjing, is written in small print, but it is elegant and smart, with a pattern of big characters. Moreover, the brushwork is exquisite, the style of writing is natural, and the style of writing is easy to decline, which is quite different from the books after the Tang Dynasty. These traces are still excellent examples of practicing small measurements.