이엄
As the fourth expedition dragged on for months, Zhuge Liang and the Wei general Sima Yi had been having a series of battles around Mount Qi, and both sides needed backup supplies. However, rainfall rendered the transportation lines impassable, and Li Yan failed to provide supplies to Zhuge Liang's camp. Instead of informing Liu Shan of the situation, Li Yan attempted to cover up his failure. Li Yan sent a letter to Zhuge Liang, informing the commander of the logistic problem, and asked the latter to return. When Zhuge Liang got back to Hanzhong Commandery, Li Yan told him that the food supply was ready and asked him why he retreated. At the same time, Li Yan sent Liu Shan a memo which says "the army feigned retreat in order to lure the enemy to do battle", hoping that Zhuge Liang would resume the war so his failure to transport supplies would go unnoticed.