According to the theory of five elements, the five elements of wood, fire, earth, gold and water correspond to the five directions of east, south, middle, west and north respectively. At the same time, it also corresponds to five heavenly stems: a, b, d, e, g and n. In addition, the five elements of wood, fire, earth, gold and water also correspond to the five colors of green, red, yellow, white and black respectively.
Therefore, according to this correspondence, if a person's name includes the heavenly stems of A, B, D, Wuji, Geng Xin and Gui Ren, then he is considered to have a special connection with wood, fire, earth, gold and water in the five elements. This correspondence is also used in the theory of five elements to explain the physiological and pathological changes of human body and the operating law of natural environment.