fact: Example tokenize_ex1 : tokenize "abc12==3 223*(3+(a+c))" %string = ["abc"; "12"; "=="; "3"; "223"; "*"; "("; "3"; "+"; "("; "a"; "+"; "c"; ")"; ")"]%string.
imports: Coq.Strings.String Coq.Strings.Ascii Coq.Arith.Arith Coq.Arith.EqNat Coq.Lists.List Maps Imp