45:9 · In China this sign has been used, from the earliest Chinese writing system to the system of today, to signify the idea of middle, in between. Together with another sign it is used to mean the Empire of the Middle, i.e. China. China was situated between heaven and the underworld and therefore was the Empire of the Middle. The only use that seems to have in the West at present is in geometry, where it stands for a quadrangle. What a waste of such a simple and beautiful structure.
    There are, however, similar signs. For example from a vulva protecting device made of clay for an Indian woman; with different meanings in several modern technical systems; and for is not equal to, in mathematics.