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Add lean source and binary files (part 67)
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import OAI.Geometry.CylinderCovering.Angular.CubicAreaDefinitions
import OAI.Geometry.CylinderCovering.Angular.Taylor
import OAI.Geometry.CylinderCovering.Angular.Margins
namespace OAI
open Set MeasureTheory
open scoped Interval
noncomputable section
namespace CylinderCovering.Cubic
lemma profile_le_one {q : ℝ} (hq : |q| ≤ 1) : profile q ≤ 1 := by
have hq2 : q ^ 2 ≤ 1 := by nlinarith [(abs_le.mp hq).1, (abs_le.mp hq).2]
have hq4 : q ^ 4 ≤ 1 := by nlinarith [sq_nonneg (q ^ 2), sq_nonneg q]
unfold profile
linarith
lemma areaDensity_identity (q : ℝ) :
2 * profile q - (((1 + q ^ 2) / 2) ^ 2 + 2 * q ^ 2) / 2 =
areaDensity q := by
unfold profile areaDensity
ring
lemma areaDensity_integral :
(∫ q in (-1 : ℝ)..1, areaDensity q) = -(1 / 15 : ℝ) := by
unfold areaDensity
have h₁ : IntervalIntegrable (fun q : ℝ => -(1 / 8 : ℝ) - q ^ 2 / 4)
volume (-1) 1 := by
apply Continuous.intervalIntegrable
fun_prop
have h₂ : IntervalIntegrable (fun q : ℝ => 7 * q ^ 4 / 8) volume (-1) 1 := by
apply Continuous.intervalIntegrable
fun_prop
have h₃ : IntervalIntegrable (fun q : ℝ => q ^ 2 / 4) volume (-1) 1 := by
apply Continuous.intervalIntegrable
fun_prop
rw [intervalIntegral.integral_add h₁ h₂,
intervalIntegral.integral_sub (continuous_const.intervalIntegrable _ _) h₃]
rw [intervalIntegral.integral_div, intervalIntegral.integral_div,
intervalIntegral.integral_const_mul, integral_pow, integral_pow,
intervalIntegral.integral_const]
norm_num
lemma inverseSqrt_bounds {x : ℝ} (hx : 0 ≤ x) :
0 ≤ 1 / Real.sqrt (1 + x) ∧
1 / Real.sqrt (1 + x) ≤ 1 ∧
|1 / Real.sqrt (1 + x) - 1| ≤ x / 2 := by
let t := Real.sqrt (1 + x)
have ht : 1 ≤ t := by
dsimp [t]
exact (Real.le_sqrt (by norm_num) (by linarith)).2 (by linarith)
have ht0 : 0 < t := by linarith
have ht2 : t ^ 2 = 1 + x := Real.sq_sqrt (by linarith)
have hu : 1 / t ≤ 1 := (div_le_one ht0).2 ht
have hl : 1 - x / 2 ≤ 1 / t := by
apply (le_div_iff₀ ht0).2
have hfac : 0 ≤ (t - 1) ^ 2 * (t + 2) :=
mul_nonneg (sq_nonneg _) (by linarith)
nlinarith only [hfac, ht2]
change 0 ≤ 1 / t ∧ 1 / t ≤ 1 ∧ |1 / t - 1| ≤ x / 2
refine ⟨by positivity, hu, ?_⟩
rw [abs_of_nonpos (by linarith : 1 / t - 1 ≤ 0)]
linarith
theorem scalar_cubic_remainder {eps D A : ℝ}
(he0 : 0 ≤ eps) (he1 : eps ≤ 1 / 2)
(hD0 : 0 ≤ D) (hD1 : D ≤ 1) (hA0 : 0 ≤ A) (hA1 : A ≤ 3) :
|(1 + eps ^ 2 * D + 100 * eps ^ 3) ^ 2 /
Real.sqrt (1 + eps ^ 2 * A) -
(1 + eps ^ 2 * (2 * D - A / 2))| ≤ 1600 * eps ^ 3 := by
let d := eps ^ 2 * D + 100 * eps ^ 3
let x := eps ^ 2 * A
let F := 1 / Real.sqrt (1 + x)
have he2 : 0 ≤ eps ^ 2 := sq_nonneg eps
have he3 : 0 ≤ eps ^ 3 := pow_nonneg he0 _
have he4 : 0 ≤ eps ^ 4 := pow_nonneg he0 _
have he32 : eps ^ 3 ≤ eps ^ 2 / 2 := by
nlinarith only [mul_le_mul_of_nonneg_right he1 he2]
have he43 : eps ^ 4 ≤ eps ^ 3 / 2 := by
nlinarith only [mul_le_mul_of_nonneg_right he1 he3]
have hd0 : 0 ≤ d := by dsimp [d]; positivity
have hd : d ≤ 51 * eps ^ 2 := by
dsimp [d]
nlinarith only [mul_le_mul_of_nonneg_left hD1 he2, he32]
have hx0 : 0 ≤ x := by dsimp [x]; positivity
have hx : x ≤ 3 * eps ^ 2 := by
dsimp [x]
nlinarith only [mul_le_mul_of_nonneg_left hA1 he2]
have hx2 : x ^ 2 ≤ 9 * eps ^ 4 := by
nlinarith only [mul_self_le_mul_self hx0 hx]
have hd2 : d ^ 2 ≤ 2601 * eps ^ 4 := by
nlinarith only [mul_self_le_mul_self hd0 hd]
have hdx : d * x ≤ 153 * eps ^ 4 := by
nlinarith only [mul_le_mul hd hx hx0 (by positivity : 0 ≤ 51 * eps ^ 2)]
obtain ⟨hF0, hF1, hFd⟩ := inverseSqrt_bounds hx0
change 0 ≤ F at hF0
change F ≤ 1 at hF1
change |F - 1| ≤ x / 2 at hFd
have hR : |F - (1 - x / 2)| ≤ (3 / 8) * x ^ 2 :=
AngularTaylor.inv_sqrt_remainder hx0
have hcross : |2 * d * (F - 1)| ≤ d * x := by
rw [abs_mul, abs_of_nonneg (by positivity : 0 ≤ 2 * d)]
nlinarith only [mul_le_mul_of_nonneg_left hFd (by positivity : 0 ≤ 2 * d)]
have hquad : |d ^ 2 * F| ≤ d ^ 2 := by
rw [abs_of_nonneg (mul_nonneg (sq_nonneg d) hF0)]
exact mul_le_of_le_one_right (sq_nonneg d) hF1
have hid : (1 + eps ^ 2 * D + 100 * eps ^ 3) ^ 2 /
Real.sqrt (1 + eps ^ 2 * A) - (1 + eps ^ 2 * (2 * D - A / 2)) =
(F - (1 - x / 2)) + 2 * d * (F - 1) + d ^ 2 * F + 200 * eps ^ 3 := by
dsimp [F, x, d]
ring
rw [hid]
have hab := abs_add_le (F - (1 - x / 2)) (2 * d * (F - 1))
have habc := abs_add_le ((F - (1 - x / 2)) + 2 * d * (F - 1)) (d ^ 2 * F)
have habcd := abs_add_le ((F - (1 - x / 2)) + 2 * d * (F - 1) + d ^ 2 * F)
(200 * eps ^ 3)
rw [abs_of_nonneg (by positivity : 0 ≤ 200 * eps ^ 3)] at habcd
nlinarith only [hab, habc, habcd, hR, hcross, hquad, hx2, hd2, hdx, he43, he3]
lemma coefficient_bounds {a b : ℝ} (ha : |a| ≤ 1) (hb : |b| ≤ 1) :
0 ≤ alpha a b ∧ alpha a b ≤ 1 ∧ |beta a b| ≤ 1 ∧
0 ≤ profileMax a b ∧ profileMax a b ≤ 1 ∧
0 ≤ speedSq a b ∧ speedSq a b ≤ 3 := by
have hab : |a * b| ≤ 1 := by
rw [abs_mul]
exact (mul_le_mul ha hb (abs_nonneg _) (by norm_num)).trans_eq (by norm_num)
have hsum : |a + b| ≤ 2 := (abs_add_le a b).trans (by linarith)
have ha0 : 0 ≤ alpha a b := by
unfold alpha
linarith [(abs_le.mp hab).1]
have ha1 : alpha a b ≤ 1 := by
unfold alpha
linarith [(abs_le.mp hab).2]
have hb1 : |beta a b| ≤ 1 := by
unfold beta
rw [abs_div]
norm_num
linarith
have hM0 : 0 ≤ profileMax a b :=
(profile_nonneg a).trans (le_max_left _ _)
have hM1 : profileMax a b ≤ 1 := max_le (profile_le_one ha) (profile_le_one hb)
refine ⟨ha0, ha1, hb1, hM0, hM1, ?_, ?_⟩
· unfold speedSq
positivity
· have ha2 : alpha a b ^ 2 ≤ 1 := by nlinarith only [ha0, ha1]
have hb2 : beta a b ^ 2 ≤ 1 := by
nlinarith only [(abs_le.mp hb1).1, (abs_le.mp hb1).2]
unfold speedSq
linarith
lemma profile_lipschitz {a q : ℝ} (ha : |a| ≤ 1) (hq : |q| ≤ 1) :
|profile a - profile q| ≤ 3 * |a - q| := by
have ha2 : a ^ 2 ≤ 1 := by nlinarith only [(abs_le.mp ha).1, (abs_le.mp ha).2]
have hq2 : q ^ 2 ≤ 1 := by nlinarith only [(abs_le.mp hq).1, (abs_le.mp hq).2]
have hsum : |a + q| ≤ 2 := (abs_add_le a q).trans (by linarith)
have hpoly : |1 + a ^ 2 + q ^ 2| ≤ 3 := by
rw [abs_of_nonneg (by positivity : 0 ≤ 1 + a ^ 2 + q ^ 2)]
linarith
have hid : profile a - profile q = (a - q) * (a + q) * (1 + a ^ 2 + q ^ 2) / 2 := by
unfold profile
ring
rw [hid, abs_div, abs_mul, abs_mul]
norm_num
have hmul := mul_le_mul hsum hpoly (abs_nonneg _) (by norm_num : (0 : ℝ) ≤ 2)
have hfinal := mul_le_mul_of_nonneg_left hmul (abs_nonneg (a - q))
nlinarith only [hfinal]
lemma profileMax_error {a b q : ℝ} (ha : |a| ≤ 1) (hb : |b| ≤ 1)
(hqa : a ≤ q) (hqb : q ≤ b) :
|profileMax a b - profile q| ≤ 3 * (b - a) := by
have hq := abs_le_of_interval ha hb hqa hqb
have h₁ := profile_lipschitz ha hq
have h₂ := profile_lipschitz hb hq
rw [abs_of_nonpos (by linarith : a - q ≤ 0)] at h₁
rw [abs_of_nonneg (by linarith : 0 ≤ b - q)] at h₂
have hlo : profile q ≤ profileMax a b := profile_le_max_endpoints hqa hqb
rw [abs_of_nonneg (sub_nonneg.mpr hlo)]
have hupper : profileMax a b ≤ profile q + 3 * (b - a) := by
apply max_le
· linarith [(abs_le.mp h₁).2]
· linarith [(abs_le.mp h₂).2]
linarith
lemma square_error {x y e : ℝ} (hx : |x| ≤ 1) (hy : |y| ≤ 1)
(hxy : |x - y| ≤ e) : |x ^ 2 - y ^ 2| ≤ 2 * e := by
have hsum : |x + y| ≤ 2 := (abs_add_le x y).trans (by linarith)
have he : 0 ≤ e := (abs_nonneg _).trans hxy
calc
|x ^ 2 - y ^ 2| = |x - y| * |x + y| := by rw [← abs_mul]; congr 1; ring
_ ≤ e * 2 := mul_le_mul hxy hsum (abs_nonneg _) he
_ = 2 * e := by ring
lemma density_error {a b q : ℝ} (ha : |a| ≤ 1) (hb : |b| ≤ 1)
(hqa : a ≤ q) (hqb : q ≤ b) :
|2 * profileMax a b - speedSq a b / 2 - areaDensity q| ≤ 8 * (b - a) := by
have hq := abs_le_of_interval ha hb hqa hqb
have hc := coefficient_bounds ha hb
have hα := alpha_error ha hq hqa hqb
have hβ := beta_error hqa hqb
have hq2 : q ^ 2 ≤ 1 := by nlinarith only [(abs_le.mp hq).1, (abs_le.mp hq).2]
have hαq : |(1 + q ^ 2) / 2| ≤ 1 := by
rw [abs_of_nonneg (by positivity : 0 ≤ (1 + q ^ 2) / 2)]
linarith
have hαabs : |alpha a b| ≤ 1 := by rw [abs_of_nonneg hc.1]; exact hc.2.1
have hαsq := square_error hαabs hαq hα
have hβsq := square_error hc.2.2.1 hq hβ
have hspeed : |speedSq a b - (((1 + q ^ 2) / 2) ^ 2 + 2 * q ^ 2)| ≤ 4 * (b - a) := by
have hid : speedSq a b - (((1 + q ^ 2) / 2) ^ 2 + 2 * q ^ 2) =
(alpha a b ^ 2 - ((1 + q ^ 2) / 2) ^ 2) + 2 * (beta a b ^ 2 - q ^ 2) := by
unfold speedSq
ring
rw [hid]
have hh := abs_add_le (alpha a b ^ 2 - ((1 + q ^ 2) / 2) ^ 2)
(2 * (beta a b ^ 2 - q ^ 2))
rw [abs_mul] at hh
norm_num at hh
linarith
have hM := profileMax_error ha hb hqa hqb
have hid : 2 * profileMax a b - speedSq a b / 2 - areaDensity q =
2 * (profileMax a b - profile q) -
(speedSq a b - (((1 + q ^ 2) / 2) ^ 2 + 2 * q ^ 2)) / 2 := by
rw [← areaDensity_identity]
ring
rw [hid]
have hh := abs_add_le (2 * (profileMax a b - profile q))
(-((speedSq a b - (((1 + q ^ 2) / 2) ^ 2 + 2 * q ^ 2)) / 2))
rw [← sub_eq_add_neg, abs_neg] at hh
rw [abs_mul, abs_div] at hh
norm_num at hh
linarith
lemma continuous_areaDensity : Continuous areaDensity := by
unfold areaDensity
fun_prop
lemma interval_density_error {a b : ℝ} (ha : |a| ≤ 1) (hb : |b| ≤ 1)
(hab : a ≤ b) :
|(b - a) * (2 * profileMax a b - speedSq a b / 2) -
(∫ q in a..b, areaDensity q)| ≤ 8 * (b - a) ^ 2 := by
have hu : ∀ q ∈ Ι a b,
‖2 * profileMax a b - speedSq a b / 2 - areaDensity q‖ ≤ 8 * (b - a) := by
intro q hq
rw [Set.uIoc_of_le hab] at hq
simpa only [Real.norm_eq_abs] using density_error ha hb hq.1.le hq.2
have h := intervalIntegral.norm_integral_le_of_norm_le_const hu
rw [intervalIntegral.integral_sub
(f := fun _ : ℝ => 2 * profileMax a b - speedSq a b / 2)
(g := areaDensity) (continuous_const.intervalIntegrable _ _)
(continuous_areaDensity.intervalIntegrable _ _), intervalIntegral.integral_const,
Real.norm_eq_abs, smul_eq_mul, abs_of_nonneg (sub_nonneg.mpr hab)] at h
nlinarith only [h]
lemma count_mul_step {N : ℕ} (hN : 0 < N) : (N : ℝ) * step N = 2 := by
have h := node_last hN
dsimp [node] at h
linarith only [h]
def areaCoefficientSum (N : ℕ) : ℝ := ∑ j : Fin N,
step N * (2 * profileMax (node N j) (node N (j + 1)) -
speedSq (node N j) (node N (j + 1)) / 2)
lemma integral_mesh_sum {N : ℕ} (hN : 0 < N) :
(∑ j : Fin N, ∫ q in node N j..node N (j + 1), areaDensity q) = -(1 / 15 : ℝ) := by
rw [Fin.sum_univ_eq_sum_range
(fun j : ℕ => ∫ q in node N j..node N (j + 1), areaDensity q) N]
rw [intervalIntegral.sum_integral_adjacent_intervals
(fun _ _ => continuous_areaDensity.intervalIntegrable _ _)]
rw [node_zero, node_last hN, areaDensity_integral]
lemma areaCoefficientSum_error {N : ℕ} (hN : 0 < N) :
|areaCoefficientSum N + 1 / 15| ≤ 16 * step N := by
have hi := integral_mesh_sum hN
have hid : areaCoefficientSum N + 1 / 15 =
∑ j : Fin N, (step N * (2 * profileMax (node N j) (node N (j + 1)) -
speedSq (node N j) (node N (j + 1)) / 2) -
∫ q in node N j..node N (j + 1), areaDensity q) := by
rw [Finset.sum_sub_distrib, hi]
dsimp [areaCoefficientSum]
ring
rw [hid]
calc
_ ≤ ∑ j : Fin N, |step N * (2 * profileMax (node N j) (node N (j + 1)) -
speedSq (node N j) (node N (j + 1)) / 2) -
∫ q in node N j..node N (j + 1), areaDensity q| :=
Finset.abs_sum_le_sum_abs _ _
_ ≤ ∑ _j : Fin N, 8 * (step N) ^ 2 := by
apply Finset.sum_le_sum
intro j _
have hab : node N j ≤ node N (j + 1) := by
have := node_succ N j
have := step_pos hN
linarith
have h := interval_density_error (node_abs_le hN j.isLt.le)
(node_abs_le hN (Nat.succ_le_of_lt j.isLt)) hab
simpa only [node_succ] using h
_ = 16 * step N := by
simp only [Finset.sum_const, Finset.card_univ, Fintype.card_fin, nsmul_eq_mul]
calc
(N : ℝ) * (8 * (step N) ^ 2) = 8 * ((N : ℝ) * step N) * step N := by ring
_ = 16 * step N := by rw [count_mul_step hN]; ring
lemma areaTerm_remainder {eps a b : ℝ} (he0 : 0 ≤ eps) (he1 : eps ≤ 1 / 2)
(ha : |a| ≤ 1) (hb : |b| ≤ 1) (hab : a ≤ b) :
|areaTerm eps a b - (b - a) * (1 + eps ^ 2 *
(2 * profileMax a b - speedSq a b / 2))| ≤ (b - a) * 1600 * eps ^ 3 := by
rcases coefficient_bounds ha hb with ⟨_, _, _, hD0, hD1, hA0, hA1⟩
have h := scalar_cubic_remainder he0 he1 hD0 hD1 hA0 hA1
have hid : areaTerm eps a b - (b - a) * (1 + eps ^ 2 *
(2 * profileMax a b - speedSq a b / 2)) =
(b - a) * ((1 + eps ^ 2 * profileMax a b + 100 * eps ^ 3) ^ 2 /
Real.sqrt (1 + eps ^ 2 * speedSq a b) -
(1 + eps ^ 2 * (2 * profileMax a b - speedSq a b / 2))) := by
unfold areaTerm cap
ring
rw [hid, abs_mul, abs_of_nonneg (sub_nonneg.mpr hab)]
nlinarith only [mul_le_mul_of_nonneg_left h (sub_nonneg.mpr hab)]
lemma areaSum_coefficient_remainder {eps : ℝ} {N : ℕ}
(he0 : 0 ≤ eps) (he1 : eps ≤ 1 / 2) (hN : 0 < N) :
|areaSum eps N - (2 + eps ^ 2 * areaCoefficientSum N)| ≤ 3200 * eps ^ 3 := by
let f : Fin N → ℝ := fun j => step N * (1 + eps ^ 2 *
(2 * profileMax (node N j) (node N (j + 1)) -
speedSq (node N j) (node N (j + 1)) / 2))
have hsum : (∑ j : Fin N, f j) = 2 + eps ^ 2 * areaCoefficientSum N := by
dsimp [f, areaCoefficientSum]
simp_rw [mul_add]
rw [Finset.sum_add_distrib, Finset.mul_sum]
have heq : (∑ j : Fin N, step N * (eps ^ 2 *
(2 * profileMax (node N j) (node N (j + 1)) -
speedSq (node N j) (node N (j + 1)) / 2))) =
∑ j : Fin N, eps ^ 2 * (step N *
(2 * profileMax (node N j) (node N (j + 1)) -
speedSq (node N j) (node N (j + 1)) / 2)) := by
apply Finset.sum_congr rfl
intro j _
ring
rw [heq]
congr 1
simp only [mul_one, Finset.sum_const, Finset.card_univ, Fintype.card_fin, nsmul_eq_mul]
exact count_mul_step hN
rw [← hsum]
unfold areaSum
rw [← Finset.sum_sub_distrib]
calc
_ ≤ ∑ j : Fin N, |areaTerm eps (node N j) (node N (j + 1)) - f j| :=
Finset.abs_sum_le_sum_abs _ _
_ ≤ ∑ _j : Fin N, step N * 1600 * eps ^ 3 := by
apply Finset.sum_le_sum
intro j _
have hab : node N j ≤ node N (j + 1) := by
have := node_succ N j
have := step_pos hN
linarith
have h := areaTerm_remainder he0 he1 (node_abs_le hN j.isLt.le)
(node_abs_le hN (Nat.succ_le_of_lt j.isLt)) hab
simpa only [node_succ, f] using h
_ = 3200 * eps ^ 3 := by
simp only [Finset.sum_const, Finset.card_univ, Fintype.card_fin, nsmul_eq_mul]
calc
(N : ℝ) * (step N * 1600 * eps ^ 3) = ((N : ℝ) * step N) * 1600 * eps ^ 3 := by ring
_ = 3200 * eps ^ 3 := by rw [count_mul_step hN]; ring
theorem areaSum_expansion {eps : ℝ} {N : ℕ}
(he0 : 0 ≤ eps) (he1 : eps ≤ 1 / 2) (hN : 0 < N)
(hstep : step N ≤ eps ^ 2) :
|areaSum eps N - (2 - eps ^ 2 / 15)| ≤ 3208 * eps ^ 3 := by
have hR := areaSum_coefficient_remainder he0 he1 hN
have hC := areaCoefficientSum_error hN
have hc : |eps ^ 2 * (areaCoefficientSum N + 1 / 15)| ≤ 8 * eps ^ 3 := by
rw [abs_mul, abs_of_nonneg (sq_nonneg _)]
have h₁ := mul_le_mul_of_nonneg_left hC (sq_nonneg eps)
have h₂ := mul_le_mul_of_nonneg_left hstep (by positivity : 0 ≤ 16 * eps ^ 2)
have h₃ := mul_le_mul_of_nonneg_right he1 (pow_nonneg he0 3)
nlinarith only [h₁, h₂, h₃]
have hid : areaSum eps N - (2 - eps ^ 2 / 15) =
(areaSum eps N - (2 + eps ^ 2 * areaCoefficientSum N)) +
eps ^ 2 * (areaCoefficientSum N + 1 / 15) := by ring
rw [hid]
exact (abs_add_le _ _).trans (by linarith only [hR, hc])
end CylinderCovering.Cubic
end
end OAI