let rec produit a b = match (a,b) with
                (0,b) -> 0
               |(a,0) -> 0
               |(1,b) -> b
               |(a,1) -> a
               |(a,b) -> b + produit (a-1) b;;

type point == float * float;;
let (creepoint: float -> float -> point) = function x -> function y -> (x,y);;
let (abscisse: point -> float) = function (x,y) -> x;;
let (ordonnee: point -> float) = function (x,y) -> y;;

let (milieu: point -> point -> point) = function A -> function B -> ((abscisse A +. abscisse B)/.2.,(ordonnee A +. ordonnee B)/.2.);;

let rec supprimeimpaire l = match l with
                [] -> []
               |t::r -> if (t mod 2 = 1) then
                         supprimeimpaire r
                        else t::supprimeimpaire r;;