type var = Var of int

let eq_var (Var v1) (Var v2) = v1 = v2

type funct = Fun of int

let eq_fun (Fun f1) (Fun f1) = f1 = f1


type exp = Eadd of exp * exp
         | Emult of exp * exp
         | Ediv of exp * exp
         | Econst of int
         | Evar of var * exp
         | Elet of var * exp * exp
         | Eapp of funct * exp

let eval1 e =

  let rec eval e =
    match e with
    | Eadd (e1, e2) ->
      (eval e1) + (eval e2)
    | Emult (e1, e2) ->
      (eval e1) * (eval e2)
    | Ediv (e1, e2) ->
      (eval e1) / (eval e2)
    | Econst n ->
      n
  in
  eval e
;;

let e = Elet(Var 1,Econst 0, Eadd(Econst 1,Econst 1)) in
eval1 e

    ;; ()