Taijitu during the Qing period for their possible connection with Zhou Dunyi's "taijitu". Ming period author Lai Zhide (1525–1604) simplified the "taijitu" to a design of two interlocking spirals. In the Ming era, the combination of the two interlocking spirals of the "taijitu" with two black-and-white dots superimposed on them became identified with the "He tu" or "Yellow River diagram" (河圖). This version was reported in Western literature of the late 19th century as the "Great Monad", and has been widely popularised in Western popular culture as the "yin-yang symbol" since the 1960s. The contemporary Chinese term for the modern symbol
Yin and yang yang are represented by broken and solid lines: yin is broken (⚋) and yang is solid (⚊). These are then combined into trigrams, which are more yang ("e.g." ☱) or more yin ("e.g." ☵) depending on the number of broken and solid lines ("e.g.", ☰ is heavily yang, while ☷ is heavily yin), and trigrams are combined into hexagrams ("e.g." ䷕ and ䷟). The relative positions and numbers of yin and yang lines within the trigrams determines the meaning of a trigram, and in hexagrams the upper trigram is considered yang with respect to the lower trigram, yin, which allows