This concept stems from The Book of Changes. "Disappearance and reappearance" signifies the cycle of departure and return pertaining to a journey, but is also extended to the abstract meaning of disappearance and reappearance of things or states of things. In the hexagram context of The Book of Changes, tai hexagram has qian (heaven) at the bottom and kun (earth) on top. This hexagram is situated at the junction of qian and kun, the pivotal point where shifts are imminent. Though qian starts from the bottom, it ultimately returns to the top, and while kun begins from the top, it eventually returns to the bottom. The concept that nothing that disappears fails to reappear uncovers the law of transformation for things or states of things.
Flat ground is not without tilt, and nothing that disappears fails to reappear. Despite the challenges brought by changes, integrity helps avert disaster. (The Book of Changes)
引例2：“无往不复”，天地际也。（《周易·象传》）（“事物循环往复”，这是天地运行的法则。）
The concept "nothing that disappears fails to reappear" symbolizes the juncture of heaven and earth. (The Book of Changes)
