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 Greek alphabet Often, in medieval manuscripts, old uncial letter forms were mixed in with the normal minuscule letters for writing titles or for emphasizing the initial letter of a word or sentence. Like in Latin, this became the root of the modern innovation of letter case, the systematic distinction between uppercase and lowercase letters in orthography. The uppercase letters of modern orthography are derived from the uncial script, while the lowercase letters are derived from minuscules. The invention of printing saw the codification of a more fixed set of letter structures. Greek handwriting made extensive use of ligatures with letters written differently