Psi (letter) (generalized) positional states of a qubit in a quantum computer. Psi is also used as the symbol for the polygamma function, defined by where formula_3 is the gamma function. The letters Ψ or ψ can also be a symbol for: These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style. Psi (letter) Psi (; uppercase ', lowercase '; "psi" ) is the 23rd letter of the Greek alphabet and has a numeric value of 700. In both Classical and Modern Greek, the letter
History of the alphabet Two variants of the Phoenician alphabet had major impacts on the history of writing: the Aramaic alphabet and the Greek alphabet. The Phoenician and Aramaic alphabets, like their Egyptian prototype, represented only consonants, a system called an "abjad". The Aramaic alphabet, which evolved from the Phoenician in the 7th century BCE, to become the official script of the Persian Empire, appears to be the ancestor of nearly all the modern alphabets of Asia: By at least the 8th century BCE the Greeks borrowed the Phoenician alphabet and adapted it to their own language, creating in the process the first "true"