Old Hollywood: Lewis sensationally revealed in her 1994 memoir that she was conceived in 1935 when Loretta Young, 22, and the married Clark Gable, 34, were shooting The Call of the Wild. Secret: Loretta Young is pictured with Judy Lewis in 1944, who did not know for years who her father was.
The sigma symbol provides the character used to denote the sum of an equation in mathematics. You can create a sigma sign by accessing the Character Palette, using a keyboard shortcut or by using the Special Characters menu in your current application.
Sigma is a Greek letter that corresponds somewhat to our letter S and thus sigma is often used to stand for some concept that starts with S. There is an upper case (capital) sigma and a lower case (small) sigma.