let max x y z = max (max x y) z;;
max 4 6 7;;
let rec pgcd a b =
  if b = 0 then a
  else pgcd b (a mod b);;
let rec power base exponent =
    if exponent = 0 then 1
    else if exponent < 0 then
      1 / power base (-exponent)
    else base * power base (exponent - 1);;
power 10 100;;

let rec fib n =
  if n <= 0 then 0.
  else if n = 1 then 1.
  else fib (n-1) +. fib (n-2);;

  let curry f (x, y) = f x y;;
  let uncurry f x y = f (x, y);;
let module_of_complex re im = sqrt (re ** 2.0 +. im ** 2.0);;

let egalite (num1, den1) (num2, den2) =
  num1 * den2 = num2 * den1;;
let rec sequence_term u n =
  if n = 0 then u
  else sequence_term (sin u) (n - 1);;

let rec u n = match n with
| 0 -> 2.0
| _ -> (u (n-1) +. v (n-1))/. 2.0
and v n = match n with
| 0 -> 1.0
| _ -> (2.0 *. v (n-1) *. u (n-1))/.(u (n-1) +. v (n-1));;

u 50;;