Module MyNat.
End MyNat.
Open Scope R_scope.
(** * Integers *)
(** Integer part in Z *)
Definition floor x := proj1_sig (floor_ex x).
Definition floor1 x := proj1_sig (floor1_ex x).
(** Interger part in nat *)
Definition nfloor x pr := proj1_sig (nfloor_ex x pr).
Definition nfloor1 x pr := proj1_sig (nfloor1_ex x pr).
(** More theorems about INR *)
Fixpoint pow2 (n : nat) : nat :=
match n with
| O => 1%nat
| S n => (2 * pow2 n)%nat
end.
(** * Rinv *)
(** * Rdiv *)
(** Rewritings *)

Lemma Rdiv_minus : forall a b c d : R, b <> 0 -> d <> 0 ->
a / b - c / d = (a * d - c * b) / (b * d).