Barter is the present and the future of international trade, especially for people who is starting in the import export business. Barter and more: Triangular operations.
Characteristics of traffic lights
Traffic lights cannot reflect the duality of language. Because language duality is when a small number of symbols (such as phonemes) convey a large number of meanings through different combinations. There are only three symbols of traffic lights: red, green, and yellow, and there are only three meanings: no passage, allowed passage, and those who have passed the line are allowed to pass. There is no other arrangement and combination, and no other information can be expressed. Therefore, although it is also divided into two levels of symbols and meanings, it cannot reflect the duality of linguistics.