Taijitu seen in Tripilja culture in Ukraine, displayed in the Ukraine pavilion at the Expo 2010 in Shanghai, China. Also, the interlocking design is found in artifacts of the European Iron Age. While this design appears to become a standard ornamental motif in Iron-Age Celtic culture by the 3rd century BC, found on a wide variety of artifacts, it is not clear what symbolic value was attached to it. Unlike the Chinese symbol, the Celtic yin-yang lack the element of mutual penetration, and the two halves are not always portrayed in different colors. Comparable designs are also found in Etruscan art.
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