let int_of_bitvector v =
  let rec aux pow v =
    match v with
      Vector.VEmpty -> 0
    | Vector.VCons (_,hd,tl) ->
        if hd = Bool.True then
          pow + (aux (pow * 2) tl)
        else
          aux (pow * 2) tl
  in
    aux 1 (Vector.reverse Nat.O v)

let rec int_of_matitapos =
 function
   Positive.One -> 1
 | Positive.P0 v -> int_of_matitapos v * 2
 | Positive.P1 v -> int_of_matitapos v * 2 + 1

let int_of_matitaZ =
 function
   Z.OZ -> 0
 | Z.Pos p -> int_of_matitapos p
 | Z.Neg p -> -(int_of_matitapos p)

let option_of_matitaoption =
 function
    Types.None -> None
  | Types.Some v -> Some v

let rec matitanat_of_int n =
 if n = 0 then Nat.O
 else if n < 0 then assert false
 else Nat.S (matitanat_of_int (n-1))

let rec int_of_matitanat =
 function
    Nat.O -> 0
  | Nat.S n -> int_of_matitanat n + 1

let int_pair_of_pointer { Pointers.pblock = bl ; Pointers.poff = off } =
  (int_of_matitaZ bl, int_of_bitvector off)