"bet" is interpreted by Kangxi dictionary as "bet, say, write and do." The Chinese Dictionary explains: "Sign or draw symbols on official documents or contracts as evidence. It also refers to the signature or drawn symbol. " It can be seen that "taking the lead" means drawing, writing and painting, that is, the action itself refers to the result of the action. During Liu Han's Northern and Southern Dynasties, the word "pledge" was popular, such as officials replying to official documents and writing "promise" or "rely on". Biography of the Later Han Dynasty contains: "Nanyang painted" infinite "for princes, and History of Northern Qi contains:" Mutipo and others sold officials and begged for books and letters. Much like the word "agree" today. Ordinary people can't read and haven't dealt with writing brushes all their lives, so symbols are used instead of Chinese characters. This originated in the Wei and Jin Dynasties and has many symbols. The most common thing is to draw a "ten" or simply draw a "χ". After history entered the Tang Dynasty, common names were written in grass. Ye Mengde's Misty Rain in the Stone Forest says: "In the early Tang Dynasty, cursive script was named as a private note", and Ouyang Xiu's Return to the Field says: "The custom takes cursive script as a token." Hong Mai's "Five Paintings of Rongzhai" also said: "Those who use ancient books as titles should apply them to literary records to prove themselves."