fact: Definition hexDigitToN (c : ascii) : option N := match c with | "0" => Some 0 | "1" => Some 1 | "2" => Some 2 | "3" => Some 3 | "4" => Some 4 | "5" => Some 5 | "6" => Some 6 | "7" => Some 7 | "8" => Some 8 | "9" => Some 9 | "a" | "A" => Some 10 | "b" | "B" => Some 11 | "c" | "C" => Some 12 | "d" | "D" => Some 13 | "e" | "E" => Some 14 | "f" | "F" => Some 15 | _ => None end.
imports: Coq.Strings.String Coq.Strings.Ascii Coq.NArith.NArith