type 'a arbre = Vide | Noeud of 'a * 'a arbre * 'a arbre;;

let rec max_arbre arbre1 = match arbre1 with
| Vide -> 0
| Noeud(r,g,d)-> max (max r (max_arbre g)) (max_arbre d)
;;

type 'a infini = Infplus| Infmoins | Valeur of 'a ;;

(* let inferieurstrict x y = match scrutinee with
| pattern -> pattern *)

type abr = Vide | Noeud of int * abr * abr;;

let rec test_abr a = match a with
| Vide -> true
| Noeud(r,g,d)-> ((r>=max_arbre g)&&(r<min_arbre)&&(test_abr g)&&(test_abr d))
;;