Mathematical notation

mathematical notation based on the Arabic script

thumb|right|250px|Example of warazan at the Museum of Science, Tokyo University of Science thumb|right|250px|Instruction to use warazan to record the level of tax assessed, in the Yaeyama-jima Kuramoto Kujichō (1873 copy of the 1857 original); the fourth to sixth characters in the fifth line from the right read「わら算」(University of the Ryukyus Library) was a system of record-keeping using knotted straw at the time of the Ryūkyū Kingdom. In the Southern Ryukyuan languages of the Sakishima Islands it was known as barazan and on Okinawa Island as warazani or warazai. Formerly used in particular in

system for describing queueing models

dual to the Dirac spinor