Shin (letter) languages, as follows: In the Arabic alphabet, ' is at the original (21st) position in Abjadi order. A letter variant ' takes the place of Samekh at 15th position. "" represents , and is the 13th letter of the modern alphabet order and is written thus: The Arabic letter "šīn" was an acronym for "something" ( "šayʾ(un)" ) meaning the unknown in algebraic equations. In the transcription into Spanish, the Greek letter "chi" (χ) was used which was later transcribed into Latin "x". According to some sources, this is the origin of "x" used for the unknown in the equations.
History of the alphabet the early western Greek dialects, where the letter eta remained an , gave rise to the Old Italic alphabet which in turn developed into the Old Roman alphabet. In the eastern Greek dialects, which did not have an /h/, eta stood for a vowel, and remains a vowel in modern Greek and all other alphabets derived from the eastern variants: Glagolitic, Cyrillic, Armenian, Gothic (which used both Greek and Roman letters), and perhaps Georgian. Although this description presents the evolution of scripts in a linear fashion, this is a simplification. For example, the Manchu alphabet, descended from the abjads of