let bot = !(/rec/ "a" . rec);
let zero = /zero suc/ zero;
let suc n = /zero suc/ suc (n zero suc);

let opt  some = _ : None | some;
let plus iter = !(/plus/ iter . (opt plus));
let star iter = opt (plus iter);

let up_to x n = n bot (/rec/ x . opt rec);

let Pattern_Whitespace = "\t"|"\n"|"\x0B"|"\x0c"|"\r"|" "|"\u{85}"|"\u{200e}"|"\u{200f}"|"\u{2028}"|"\u{2029}";

match = "0" |"1";