Commit 337d4525 authored by MARCHE Claude's avatar MARCHE Claude

Coq proof of cosine

parent eb71c6c4
(* Beware! Only edit allowed sections below *)
(* This file is generated by Why3's Coq driver *)
Require Import ZArith.
Require Import Rbase.
Require Import Rbasic_fun.
Require Import R_sqrt.
Require Import Rtrigo.
Require Import AltSeries. (* for def of pi *)
Axiom Refl : forall (x:R), (x <= x)%R.
Axiom Trans : forall (x:R) (y:R) (z:R), (x <= y)%R -> ((y <= z)%R ->
(x <= z)%R).
Axiom Antisymm : forall (x:R) (y:R), (x <= y)%R -> ((y <= x)%R -> (x = y)).
Axiom Total : forall (x:R) (y:R), (x <= y)%R \/ (y <= x)%R.
Axiom Abs_le : forall (x:R) (y:R), ((Rabs x) <= y)%R <-> (((-y)%R <= x)%R /\
(x <= y)%R).
Axiom Abs_pos : forall (x:R), ((Rabs x) >= (0)%R)%R.
Axiom Sqrt_positive : forall (x:R), (x >= (0)%R)%R -> ((sqrt x) >= (0)%R)%R.
Axiom Sqrt_square : forall (x:R), (x >= (0)%R)%R -> ((Rsqr (sqrt x)) = x).
Axiom Square_sqrt : forall (x:R), (x >= (0)%R)%R -> ((sqrt (x * x)%R) = x).
Axiom Pythagorean_identity : forall (x:R),
(((Rsqr (Rtrigo_def.cos x)) + (Rsqr (Rtrigo_def.sin x)))%R = (1)%R).
Axiom Cos_le_one : forall (x:R), ((Rabs (Rtrigo_def.cos x)) <= (1)%R)%R.
Axiom Sin_le_one : forall (x:R), ((Rabs (Rtrigo_def.sin x)) <= (1)%R)%R.
Axiom Cos_0 : ((Rtrigo_def.cos (0)%R) = (1)%R).
Axiom Sin_0 : ((Rtrigo_def.sin (0)%R) = (0)%R).
Axiom Pi_interval : ((314159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111745028410270193852110555964462294895493038196 / 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000)%R < PI)%R /\
(PI < (314159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111745028410270193852110555964462294895493038197 / 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000)%R)%R.
Axiom Cos_pi : ((Rtrigo_def.cos PI) = (-(1)%R)%R).
Axiom Sin_pi : ((Rtrigo_def.sin PI) = (0)%R).
Axiom Cos_pi2 : ((Rtrigo_def.cos ((05 / 10)%R * PI)%R) = (0)%R).
Axiom Sin_pi2 : ((Rtrigo_def.sin ((05 / 10)%R * PI)%R) = (1)%R).
Axiom Cos_plus_pi : forall (x:R),
((Rtrigo_def.cos (x + PI)%R) = (-(Rtrigo_def.cos x))%R).
Axiom Sin_plus_pi : forall (x:R),
((Rtrigo_def.sin (x + PI)%R) = (-(Rtrigo_def.sin x))%R).
Axiom Cos_plus_pi2 : forall (x:R),
((Rtrigo_def.cos (x + ((05 / 10)%R * PI)%R)%R) = (-(Rtrigo_def.sin x))%R).
Axiom Sin_plus_pi2 : forall (x:R),
((Rtrigo_def.sin (x + ((05 / 10)%R * PI)%R)%R) = (Rtrigo_def.cos x)).
Axiom Cos_neg : forall (x:R), ((Rtrigo_def.cos (-x)%R) = (Rtrigo_def.cos x)).
Axiom Sin_neg : forall (x:R),
((Rtrigo_def.sin (-x)%R) = (-(Rtrigo_def.sin x))%R).
Axiom Cos_sum : forall (x:R) (y:R),
((Rtrigo_def.cos (x + y)%R) = (((Rtrigo_def.cos x) * (Rtrigo_def.cos y))%R - ((Rtrigo_def.sin x) * (Rtrigo_def.sin y))%R)%R).
Axiom Sin_sum : forall (x:R) (y:R),
((Rtrigo_def.sin (x + y)%R) = (((Rtrigo_def.sin x) * (Rtrigo_def.cos y))%R + ((Rtrigo_def.cos x) * (Rtrigo_def.sin y))%R)%R).
Parameter atan: R -> R.
Axiom Tan_atan : forall (x:R), ((Rtrigo.tan (atan x)) = x).
Inductive mode :=
| nearestTiesToEven : mode
| toZero : mode
| up : mode
| down : mode
| nearTiesToAway : mode .
Parameter single : Type.
Definition max_single: R := (33554430 * 10141204801825835211973625643008)%R.
Definition max_int: Z := 16777216%Z.
Axiom Zero : ((IZR 0%Z) = (0)%R).
Axiom One : ((IZR 1%Z) = (1)%R).
Axiom Add : forall (x:Z) (y:Z), ((IZR (x + y)%Z) = ((IZR x) + (IZR y))%R).
Axiom Sub : forall (x:Z) (y:Z), ((IZR (x - y)%Z) = ((IZR x) - (IZR y))%R).
Axiom Mul : forall (x:Z) (y:Z), ((IZR (x * y)%Z) = ((IZR x) * (IZR y))%R).
Axiom Neg : forall (x:Z) (y:Z), ((IZR (-x)%Z) = (-(IZR x))%R).
Parameter round: mode -> R -> R.
Parameter round_logic: mode -> R -> single.
Parameter value: single -> R.
Parameter exact: single -> R.
Parameter model: single -> R.
Definition round_error(x:single): R := (Rabs ((value x) - (exact x))%R).
Definition total_error(x:single): R := (Rabs ((value x) - (model x))%R).
Definition no_overflow(m:mode) (x:R): Prop := ((Rabs (round m
x)) <= (max_single ))%R.
Axiom Bounded_real_no_overflow : forall (m:mode) (x:R),
((Rabs x) <= (max_single ))%R -> (no_overflow m x).
Axiom Round_monotonic : forall (m:mode) (x:R) (y:R), (x <= y)%R -> ((round m
x) <= (round m y))%R.
Axiom Exact_rounding_for_integers : forall (m:mode) (i:Z),
(((-(max_int ))%Z <= i)%Z /\ (i <= (max_int ))%Z) -> ((round m
(IZR i)) = (IZR i)).
Axiom Round_down_le : forall (x:R), ((round (down ) x) <= x)%R.
Axiom Round_up_ge : forall (x:R), ((round (up ) x) >= x)%R.
Axiom Round_down_neg : forall (x:R), ((round (down ) (-x)%R) = (-(round (up )
x))%R).
Axiom Round_up_neg : forall (x:R), ((round (up ) (-x)%R) = (-(round (down )
x))%R).
Theorem MethodError : forall (x:R), ((Rabs x) <= (1 / 32)%R)%R ->
((Rabs (((1)%R - ((x * x)%R * (05 / 10)%R)%R)%R - (Rtrigo_def.cos x))%R) <= (1 / 16777216)%R)%R.
(* YOU MAY EDIT THE PROOF BELOW *)
intros x H.
Require Import Interval_tactic.
interval with (i_bisect_diff x).
Qed.
(* DO NOT EDIT BELOW *)
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