Xingyi Boxing ( 形意拳 Xingyi Quan ) was originally known as Xinyi Boxing ( 心意拳 Xinyi Quan ), which means boxing by carrying out the mind's will. Later it was mistaken as Xingyi Boxing, which means boxing by form and will. Legendarily transmitted by Yue Fei, this type of Boxing holds the five agents ( 五行 Wuxing ) and twelve forms as its essence, and the eight movements of spreading, cutting, swathing, straddling, stabbing, clouding, and leading as its functions. Its basic training method is pole standing ( 站樁 Zhanzhuang ) and steady squatting. The key formulae of Xingyi Pole Standing ( 形意樁 Xingyi Zhuang ) are: but up the head, straighten the neck, droop the shoulders, contract the crotch, stretch the forearm, wrap the elbows, erect the knees, contract the anus, and hold the palms down. Xingyi Boxing comprises the boxing of the Five Agents (cleaving, blocking, assembling, rubbing, and crossing correspond to metal, wood, water, fire and earth), the boxing of the twelve forms (dragon, tiger, monkey, horse, cock, swallow, snipe, snake, eagle and bear), and the boxing of interlinked advance and retreat. It has developed into the art of the sword and the art of the spear. This type of boxing starts with obvious strength, develops into hidden strength and ends with melting strength reaching the ends of the hands and feet. Its later developments integrated its strong points into a grand art.