The existent scholarship shows that the compositional structure of the four couplets in a regulated poem as "Introduction, Development, Contrast, and Conclusion" was first proposed by Yang Zai and Fan Peng in the Yuan Dynasty. Yang Zai summarized various comments and arguments on metric prosody in the Tang and Song dynasties, modified by his own views, while Fan Peng argued that the structuring might apply not only to regulated verse but to all the literary creation. Fan Peng had also proposed his own criteria for the structuring of regulated verse, based perhaps on his own Jiangxi local poetics. Fan Peng's structure for regulated verse became more prominent and was later debated among the Ming and Qing dynasties poetic scholars, with the revivalists in the Ming dynasty generally accepting Fan's proposition and Xu Zeng and Wang Shizhen in the Qing dynasty disapproving it on the basis of their own poetic agenda. While being ridiculed for its rigidity by such scholars as Feng Ban and Wu Qiao in the Qing dynasty, Fan Peng's structure for regulated verse was generally believed to be sound as an introductory approach to enlighten children, which was practiced in the Ming and Qing dynasties till today．