Xi (letter) dialects of most of the Greek mainland and Euboea, the sound [ks] was represented by Χ (which in classical Greek is chi, used for ). Because this variant of the Greek alphabet was used in Italy, the Latin alphabet borrowed Χ rather than Ξ as the Latin letter X. While having no Latin derivative, the Xi was adopted into the early Cyrillic alphabet, as the letter ksi (Ѯ, ѯ). The uppercase letter Ξ is used as symbol for: The lowercase letter ξ is used as a symbol for: These characters are used only as mathematical symbols. Stylized Greek text should
Nu (letter) Nu (letter) Nu (; uppercase Ν lowercase ν; "ni" ) or ny is the 13th letter of the Greek alphabet. In the system of Greek numerals it has a value of 50. It is derived from the ancient Phoenician language nun . Its Latin equivalent is N, though the lowercase resembles the Roman lowercase v (formula_1). The name of the letter is written in Ancient Greek and traditional Modern Greek polytonic orthography, while in Modern Greek it is written . The uppercase Nu is not used, because it is normally identical to Latin N. The lower-case letter ν is used