let rec fact n =
  if n = 0 then 1
  else n * fact (pred n)

let test_fact0 () =
  begin
    assert (fact 0 = 1);
    assert (fact 6 = 720);
  end

let unit_test name condition =
  begin
    print_string ("Testing " ^ name);
    if condition then print_endline " Passed"
    else
      begin
        print_endline " Failed";
        flush stdout;
      end
  end

let test_fact () =
  begin
    unit_test "fact 0" (fact 0 = 1);
    unit_test "fact 6" (fact 6 = 720);
    unit_test "toto" (fact 7 = 720);
  end

(* Zones géométriques représentées par leur fonction caractéristique *)
type point = mycomplex

type zone = point -> bool

let make_point x y = make_complex x y

let everywhere = fun point -> true

let nowhere = fun point -> false

let point_in_zone_p point (zone : zone) = zone point

let origine = make_point 0. 0.

let p10 = make_point 10. 10.

let make_disk0 radius : zone =
  fun point -> c_abs point <= radius

let translate_zone zone vector : zone =
  fun point -> 
  point_in_zone_p (translate point (c_opp vector)) zone

(* types inductifs *)
type intlist = NI | CI of int * intlist

type 'a mylist = Nil | C of 'a * 'a mylist

let rec length l =
  match l with
    Nil -> 0
  | C(_, l') -> length l' + 1