//$use Dos StdIO; //"timer";
$use StdIO;

$func  MkArg  eString = ePrefixes;
$func  Select (eXs) eSets = eXs-or-sFail; * (eXs) or '*'
$func  OneOf  (eXs) sX = sBool-T-or-F;

Main = /*<PrintLN <Time>>,*/ 
  <MkArg '1234567890ab'> :: e.Prefixes,
  <PrintLN e.Prefixes>,
  <Select () e.Prefixes> :: eXs-or-sFail,
  <PrintLN eXs-or-sFail>,
  //<PrintLN  t.StartTime>,
  /*<PrintLN <Time>>*/;

MkArg e.String = * e.Prefixes
  e.String : {  
    e.String-- s = (e.String) <MkArg e.String-->;
    /* empty */  = ;
  };

Select (e.Xs) e.Sets = * e.Xs-or-sFail -- (eXs) or '*'
  e.Sets : {
    /*empty*/ = (e.Xs);

    (e.Set) e.Sets--,
      e.Set : e sX e, 
      <OneOf (e.Xs) sX> : F, 
      <Select (e.Xs sX) e.Sets--> : (e.Xs-) = (e.Xs-);

    e = '+';
  };

OneOf (e.Xs) s.X =
  e.Xs : {
    e sX e = T;

    e      = F;
  };