(** Commutation properties with addition, subtraction, multiplication. *)

(* Specifications: *)
Theorem BofZ_plus:
forall nan p q,
integer_representable p -> integer_representable q ->
Bplus _ _ _ Hmax nan mode_NE (BofZ p) (BofZ q) = BofZ (p + q).
Theorem BofZ_minus:
forall nan p q,
integer_representable p -> integer_representable q ->
Bminus _ _ _ Hmax nan mode_NE (BofZ p) (BofZ q) = BofZ (p - q).
Theorem BofZ_mult:
forall nan p q,
integer_representable p -> integer_representable q ->
0 < q ->
Bmult _ _ _ Hmax nan mode_NE (BofZ p) (BofZ q) = BofZ (p * q).
Theorem BofZ_mult_2p:
forall nan x p,
Z.abs x <= 2^emax - 2^(emax-prec) ->
2^prec <= Z.abs x ->
0 <= p <= emax - 1 ->
Bmult _ _ _ Hmax nan mode_NE (BofZ x) (BofZ (2^p)) = BofZ (x * 2^p).