Formal language

Definition: closure of an alphabet , Kleene star Given an alphabet , the *, is the language containing all words made up of finite sequences of letters from , including the empty string . closure of (or Kleene star), denoted Examples: . {x} .-0, 1 } * {A, x, xx, xxx, } *-A, 0, 1,00, 01, 10, 11,000, 001, }