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 these words. From the Eastern Greek alphabet, they borrowed Y and Z, which were added to the end of the alphabet because the only time they were used was to write Greek words. The Anglo-Saxons began using Roman letters to write Old English as they converted to Christianity, following Augustine of Canterbury's mission to Britain in the sixth century. Because the Runic "wen", which was first used to represent the sound 'w' and looked like a p that is narrow and triangular, was easy to confuse with an actual p, the 'w' sound began to be written using a double