TRS:
 {       le(0(), y) -> true(),
      le(s(x), 0()) -> false(),
     le(s(x), s(y)) -> le(x, y),
          int(x, y) -> if(le(x, y), x, y),
   if(true(), x, y) -> cons(x, int(s(x), y)),
  if(false(), x, y) -> nil()}
 Fail