(* Shift F5 *)

let f x =
  (sqrt x +. log x) *. (sqrt x -. log x)

let f2 x =
  let v1 = sqrt x
  and v2 = log x in
  (v1 +. v2) *. (v1 -. v2)

let f3 x =
  let v1, v2 = sqrt x, log x in
  (v1 +. v2) *. (v1 -. v2)

let g x = sqrt x +. log (sqrt x)

let g2 x =
  let v1 = sqrt x in
  let v2 = log v1 in
  v1 +. v2

let rec fact n =
  if n = 0 then
    1
  else n * fact n

let rec pow2 x = (* lineaire *)
  if x = 0 then 1
  else 2 * pow2 (x - 1)

let rec pow2_log x = (* log *)
  if x = 0 then 1
  else let y = pow2_log (x / 2) in
       let c = y * y in
       if x mod 2 = 0 then
         c
       else c * 2