let rec compare_list (l1:int list) l2 =
  match l1 with
  | [] -> true
  | x::xs ->
     match l2 with
     | [] -> false
     | y::ys ->
	if x = y then
	  compare_list xs ys
	else
	  x < y


let rec insert le x l =
  match l with
  | [] -> [x]
  | y::ys ->
     if le y x then y::insert le x ys
     else x::y::ys

		  
let rec isort le l =
  match l with
  | [] -> []
  | x::xs -> insert le x (isort le xs)

let isort_list = isort compare_list

let l1 = [1;2;3;4;5]
let l2 = [1;2;3;4;4]
let l3 = [1;2;3;4]
let l4 = [1;2;3;4;4;4]
let l5 = [1;1;3;4;4;4]
let l6 = [-1;0;1;2;3;4]
let l7 = [1;2;3;5;5]
let l8 = []
	   
let _ = isort_list [l1;l2;l3;l4;l5;l6;l7;l8]