openAI-math-dataset / lean /OAI /Geometry /CubicTorus /Profiles /SectionExtentBounds.lean
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import Mathlib
import OAI.Geometry.CubicTorus.Reflection.AxialAreaDensity
namespace OAI
section
section
noncomputable section
open MeasureTheory Set Filter
open scoped ENNReal NNReal Topology RealInnerProductSpace
namespace CubicTorus
theorem isMinimizerAt_section_complement_both_extents {V : ℝ} (hV : V∈Ioo 0 1)
{E : Set Torus} (hmin : IsMinimizerAt V E)
(hR : ∀ i : Fin 3,E=ᵐ[torusVolume]((axisReflection i).torus ⁻¹' E))
{b : Fin 3 →Bool}
(hd : ∀ x∈upperOctant,∀ y∈upperOctant,OrientedCoordinateLE b x y →
quotientMap y∈openRepresentative E →quotientMap x∈openRepresentative E)
(i : Fin 3) (t : ℝ)
(hout : quotientMap (axialSectionCorner b i t (fun _ ↦ true))∉closure (openRepresentative E))
(hin0 : quotientMap (axialSectionCorner b i t (fun j ↦ j==0))∈openRepresentative E)
(hin1 : quotientMap (axialSectionCorner b i t (fun j ↦ j==1))∈openRepresentative E)
(hn : volume (axialSlice (frontier (openRepresentative E)) i (t : AxisCircle))=0)
(j : Fin 2) :
∃ L : ℝ,L∈Ioo 0 (1/2) ∧
(∀ y∈centeredAxialSlice (openRepresentative Eᶜ) (fun k ↦ !b k) i (t : AxisCircle),‖y j‖<L) ∧
(∀ y : TransverseProduct,(∀ k : Fin 2,k≠j →y k=0) →‖y j‖<L →
y∈centeredAxialSlice (openRepresentative Eᶜ) (fun k ↦ !b k) i (t : AxisCircle)) ∧
ENNReal.ofReal ((1-volume.real (axialSlice (openRepresentative E) i (t : AxisCircle)))/L+Real.pi*L)≤
planarTorusPerimeter (axialSlice (openRepresentative E) i (t : AxisCircle)) := by
have hVc : 1-V∈Ioo (0 : ℝ) 1 := ⟨by linarith [hV.2],by linarith [hV.1]⟩
have hmc := (isMinimizerAt_compl ⟨hV.1.le,hV.2.le⟩).mpr hmin
have hRc (i : Fin 3) : Eᶜ=ᵐ[torusVolume]((axisReflection i).torus ⁻¹' Eᶜ) := (hR i).compl
have hdc := isMinimizerAt_complement_octant_downset hV hmin hR hd
have hswap0 : (fun j : Fin 2 ↦ !(j==0))=(fun j ↦ j==1) := by funext j; fin_cases j <;> decide
have hswap1 : (fun j : Fin 2 ↦ !(j==1))=(fun j ↦ j==0) := by funext j; fin_cases j <;> decide
have hin : quotientMap (axialSectionCorner (fun k ↦ !b k) i t (fun _ ↦ false))∈openRepresentative Eᶜ := by
rw [openRepresentative_compl_eq hV hmin,axialSectionCorner_reverse]
exact hout
have hv0 : quotientMap (axialSectionCorner (fun k ↦ !b k) i t (fun j ↦ j==0))∉closure (openRepresentative Eᶜ) := by
rw [closure_openRepresentative_compl_eq hV hmin,axialSectionCorner_reverse,hswap0]
simpa using hin1
have hv1 : quotientMap (axialSectionCorner (fun k ↦ !b k) i t (fun j ↦ j==1))∉closure (openRepresentative Eᶜ) := by
rw [closure_openRepresentative_compl_eq hV hmin,axialSectionCorner_reverse,hswap1]
simpa using hin0
obtain ⟨L,hL,hband,hfill,hp⟩ := isMinimizerAt_section_both_extents hVc hmc hRc hdc i t hin hv0 hv1 j
rw [axialSlice_complement_volume hV hmin i _ hn,axialSlice_complement_perimeter hV hmin i _ hn] at hp
exact ⟨L,hL,hband,hfill,hp⟩
end CubicTorus
end
end
section
noncomputable section
open MeasureTheory Set Filter
open scoped ENNReal NNReal Topology RealInnerProductSpace
namespace CubicTorus
theorem isMinimizerAt_bottom_both_extents {V : ℝ} (hV : V∈Ioo 0 1)
{E : Set Torus} (hE : MeasurableSet E) (hmin : IsMinimizerAt V E)
(hR : ∀ i : Fin 3,E=ᵐ[torusVolume]((axisReflection i).torus ⁻¹' E))
(b : Fin 3 →Bool)
(hd : ∀ x∈upperOctant,∀ y∈upperOctant,OrientedCoordinateLE b x y →
quotientMap y∈openRepresentative E →quotientMap x∈openRepresentative E)
{μ : FiniteMeasure NormalBundle} (hμ : IsNormalMeasure E μ) {H : ℝ}
(hCMC : ∀ F : Cover → Cover,ContDiff ℝ (⊤ : ℕ∞) F →
(∀ m x,F (x+latticeVector m)=F x) →
(∫ z,tangentialDivergence F z.1 z.2 ∂(μ : Measure NormalBundle))=
H*(∫ z,⟪(z.2 : Cover),F z.1⟫ ∂(μ : Measure NormalBundle)))
(i : Fin 3) (ha : (axialAreaMarginal μ i : Measure AxisCircle)≪volume)
(hv : quotientMap (orientedUpperVertex b (fun j ↦ if j=i then true else false))∉openRepresentative E)
(hout : quotientMap (axialSectionCorner b i (octantHeight b i 0) (fun _ ↦ true))∉closure (openRepresentative E))
(hin0 : quotientMap (axialSectionCorner b i (octantHeight b i 0) (fun j ↦ j==0))∈openRepresentative E)
(hin1 : quotientMap (axialSectionCorner b i (octantHeight b i 0) (fun j ↦ j==1))∈openRepresentative E) :
let s := volume.real (axialSlice (openRepresentative E) i (octantHeight b i 0 : AxisCircle))
0<H*s ∧ Real.pi*(1-s)≤((H/2)*s)^2 ∧
∀ j : Fin 2,∃ L : ℝ,L∈Ioo 0 1 ∧
(∀ y∈centeredAxialSlice (openRepresentative Eᶜ) (fun k ↦ !b k) i (octantHeight b i 0 : AxisCircle),2*‖y j‖<L) ∧
(∀ y : TransverseProduct,(∀ k : Fin 2,k≠j →y k=0) →2*‖y j‖<L →
y∈centeredAxialSlice (openRepresentative Eᶜ) (fun k ↦ !b k) i (octantHeight b i 0 : AxisCircle)) ∧
(1-s)/L+Real.pi*L/4≤(H/2)*s := by
dsimp only
let s := volume.real (axialSlice (openRepresentative E) i (octantHeight b i 0 : AxisCircle))
obtain ⟨hHs,hdisc,_⟩ := isMinimizerAt_bottom_extent_calibration hV hE hmin hR b hd hμ hCMC i ha hv hout hin0 hin1
refine ⟨hHs,hdisc,fun j ↦ ?_⟩
have hn := isMinimizerAt_boundary_slice_null hV hE hmin hμ i ha (octantHeight b i 0 : AxisCircle)
obtain ⟨L,hL,hband,hfill,hcal⟩ := isMinimizerAt_section_complement_both_extents hV hmin hR hd i (octantHeight b i 0) hout hin0 hin1 hn j
have hp := isMinimizerAt_missing_neighbor_seam_bound hV hE hmin hR b hd hμ hCMC i ha hv
have hcal' : (1-s)/L+Real.pi*L≤H*s :=
(ENNReal.ofReal_le_ofReal_iff hHs.le).mp (hcal.trans hp)
refine ⟨2*L,⟨mul_pos (by norm_num) hL.1,by linarith [hL.2]⟩,?_,?_,?_⟩
· intro y hy
linarith [hband y hy]
· intro y hy hyL
exact hfill y hy (by linarith)
· have he : (1-s)/(2*L)+Real.pi*(2*L)/4=((1-s)/L+Real.pi*L)/2 := by field_simp; ring
rw [he]
nlinarith [hcal']
end CubicTorus
end
end
section
noncomputable section
open Set MeasureTheory
open scoped ENNReal
namespace CubicTorus.Nesting
def lambda : ℝ := 49 / 50
def ell : ℝ := 7 / 25
def cutoff : ℝ := Real.sqrt 48 / 7
def rawWeight (X : ℝ) : ℝ := (1 - lambda * X ^ 2) / Real.sqrt (1 - X ^ 2)
def weight (X : ℝ) : ℝ := rawWeight (min X cutoff)
def fluxAux (J X : ℝ) : ℝ :=
1 / X - lambda * X - J * (Real.sqrt (1 - X ^ 2) / X)
def fluxAuxDeriv (J X : ℝ) : ℝ :=
-1 / X ^ 2 - lambda + J / (X ^ 2 * Real.sqrt (1 - X ^ 2))
def fluxAuxSecond (J X : ℝ) : ℝ :=
2 / X ^ 3 + J * (3 * X ^ 2 - 2) /
(X ^ 3 * (Real.sqrt (1 - X ^ 2)) ^ 3)
lemma sqrt_pos_of_mem_Ioo {x : ℝ} (hx : x ∈ Ioo 0 1) :
0 < Real.sqrt (1 - x ^ 2) := by
apply Real.sqrt_pos.2
nlinarith [hx.1, hx.2, sq_nonneg x]
lemma sqrt_square_of_mem_Ioo {x : ℝ} (hx : x ∈ Ioo 0 1) :
Real.sqrt (1 - x ^ 2) ^ 2 = 1 - x ^ 2 := by
apply Real.sq_sqrt
nlinarith [hx.1, hx.2, sq_nonneg x]
lemma hasDerivAt_sqrt_one_sub_sq {x : ℝ} (hx : x ∈ Ioo 0 1) :
HasDerivAt (fun y : ℝ => Real.sqrt (1 - y ^ 2))
(-x / Real.sqrt (1 - x ^ 2)) x := by
have hp : 0 < 1 - x ^ 2 := by nlinarith [hx.1, hx.2, sq_nonneg x]
convert ((hasDerivAt_const x (1 : ℝ)).sub ((hasDerivAt_id x).pow 2)).sqrt
(ne_of_gt hp) using 1
· rfl
· dsimp
ring
lemma hasDerivAt_fluxAux {J x : ℝ} (hx : x ∈ Ioo 0 1) :
HasDerivAt (fluxAux J) (fluxAuxDeriv J x) x := by
have hx0 : x ≠ 0 := ne_of_gt hx.1
have hs0 : Real.sqrt (1 - x ^ 2) ≠ 0 := ne_of_gt (sqrt_pos_of_mem_Ioo hx)
have hs2 := sqrt_square_of_mem_Ioo hx
have hs := hasDerivAt_sqrt_one_sub_sq hx
have hh := (((hasDerivAt_const x (1 : ℝ)).div (hasDerivAt_id x) hx0).sub
((hasDerivAt_id x).const_mul lambda)).sub
((hs.div (hasDerivAt_id x) hx0).const_mul J)
convert hh using 1 <;> try rfl
dsimp [fluxAuxDeriv]
field_simp [hx0, hs0]
linear_combination -J * hs2
lemma hasDerivAt_fluxAuxDeriv {J x : ℝ} (hx : x ∈ Ioo 0 1) :
HasDerivAt (fluxAuxDeriv J) (fluxAuxSecond J x) x := by
have hx0 : x ≠ 0 := ne_of_gt hx.1
have hs0 : Real.sqrt (1 - x ^ 2) ≠ 0 := ne_of_gt (sqrt_pos_of_mem_Ioo hx)
have hs2 := sqrt_square_of_mem_Ioo hx
have hs := hasDerivAt_sqrt_one_sub_sq hx
have hsq := (hasDerivAt_id x).pow 2
have hh := (((hasDerivAt_const x (-1 : ℝ)).div hsq (pow_ne_zero 2 hx0)).sub
(hasDerivAt_const x lambda)).add
((hasDerivAt_const x J).div (hsq.mul hs) (mul_ne_zero (pow_ne_zero 2 hx0) hs0))
convert hh using 1 <;> try rfl
dsimp [fluxAuxSecond]
field_simp [hx0, hs0]
linear_combination 2 * J * hs2
lemma fluxAuxSecond_nonneg {J x : ℝ} (hJ : J ∈ Icc 0 1) (hx : x ∈ Ioo 0 1) :
0 ≤ fluxAuxSecond J x := by
have hs : 0 < Real.sqrt (1 - x ^ 2) := sqrt_pos_of_mem_Ioo hx
have hs2 := sqrt_square_of_mem_Ioo hx
unfold fluxAuxSecond
have hx0 := ne_of_gt hx.1
have hs0 := ne_of_gt hs
rw [show 2 / x ^ 3 + J * (3 * x ^ 2 - 2) /
(x ^ 3 * Real.sqrt (1 - x ^ 2) ^ 3) =
(2 * Real.sqrt (1 - x ^ 2) ^ 3 + J * (3 * x ^ 2 - 2)) /
(x ^ 3 * Real.sqrt (1 - x ^ 2) ^ 3) by field_simp]
apply div_nonneg _ (le_of_lt (mul_pos (pow_pos hx.1 _) (pow_pos hs _)))
have hid : 2 * Real.sqrt (1 - x ^ 2) ^ 3 + J * (3 * x ^ 2 - 2) =
(1 - J) * (2 * Real.sqrt (1 - x ^ 2) ^ 3) +
J * ((Real.sqrt (1 - x ^ 2) - 1) ^ 2 * (2 * Real.sqrt (1 - x ^ 2) + 1)) := by
linear_combination 3 * J * hs2
rw [hid]
exact add_nonneg (mul_nonneg (sub_nonneg.mpr hJ.2) (by positivity))
(mul_nonneg hJ.1 (mul_nonneg (sq_nonneg _) (by positivity)))
lemma continuousOn_fluxAux {ε : ℝ} (hε : 0 < ε) (J : ℝ) :
ContinuousOn (fluxAux J) (Icc ε 1) := by
have hn : ∀ x ∈ Icc ε (1 : ℝ), x ≠ 0 := fun _ hx => ne_of_gt (lt_of_lt_of_le hε hx.1)
have hc : Continuous (fun x : ℝ => Real.sqrt (1 - x ^ 2)) :=
Real.continuous_sqrt.comp (continuous_const.sub (continuous_id.pow 2))
exact ((continuousOn_const.div continuousOn_id hn).sub
(continuousOn_const.mul continuousOn_id)).sub
(continuousOn_const.mul (hc.continuousOn.div continuousOn_id hn))
lemma convexOn_fluxAux {ε J : ℝ} (hε : 0 < ε) (hJ : J ∈ Icc 0 1) :
ConvexOn ℝ (Icc ε 1) (fluxAux J) := by
refine convexOn_of_hasDerivWithinAt2_nonneg (f' := fluxAuxDeriv J)
(f'' := fluxAuxSecond J) (convex_Icc ε 1) (continuousOn_fluxAux hε J) ?_ ?_ ?_
· intro x hx
rw [interior_Icc] at hx
exact (hasDerivAt_fluxAux ⟨lt_trans hε hx.1, hx.2⟩).hasDerivWithinAt
· intro x hx
rw [interior_Icc] at hx
exact (hasDerivAt_fluxAuxDeriv ⟨lt_trans hε hx.1, hx.2⟩).hasDerivWithinAt
· intro x hx
rw [interior_Icc] at hx
exact fluxAuxSecond_nonneg hJ ⟨lt_trans hε hx.1, hx.2⟩
lemma cutoff_pos : 0 < cutoff := by
unfold cutoff
positivity
lemma cutoff_sq : cutoff ^ 2 = 48 / 49 := by
norm_num [cutoff, div_pow]
lemma cutoff_lt_one : cutoff < 1 := by
nlinarith [cutoff_sq, cutoff_pos]
lemma sqrt_cutoff : Real.sqrt (1 - cutoff ^ 2) = 1 / 7 := by
rw [cutoff_sq]
norm_num
lemma rawWeight_cutoff : rawWeight cutoff = ell := by
rw [rawWeight, sqrt_cutoff, cutoff_sq]
norm_num [lambda, ell]
lemma rawWeight_lower {x : ℝ} (hx : x ∈ Ico 0 1) : ell ≤ rawWeight x := by
have hrad : 0 < 1 - x ^ 2 := by nlinarith [hx.1, hx.2, sq_nonneg x]
have hs : 0 < Real.sqrt (1 - x ^ 2) := Real.sqrt_pos.2 hrad
have hs2 := Real.sq_sqrt (le_of_lt hrad)
unfold rawWeight ell lambda
apply (le_div_iff₀ hs).2
nlinarith [sq_nonneg (7 * Real.sqrt (1 - x ^ 2) - 1)]
lemma hasDerivAt_rawWeight {x : ℝ} (hx : x ∈ Ioo 0 1) :
HasDerivAt rawWeight
(x * (49 * x ^ 2 - 48) / (50 * Real.sqrt (1 - x ^ 2) ^ 3)) x := by
have hs := hasDerivAt_sqrt_one_sub_sq hx
have hs0 := ne_of_gt (sqrt_pos_of_mem_Ioo hx)
have hs2 := sqrt_square_of_mem_Ioo hx
have hh := ((hasDerivAt_const x (1 : ℝ)).sub
(((hasDerivAt_id x).pow 2).const_mul lambda)).div hs hs0
convert hh using 1 <;> try rfl
dsimp [lambda]
field_simp
linear_combination 98 * x * hs2
lemma continuousOn_rawWeight : ContinuousOn rawWeight (Icc 0 cutoff) := by
have hs : ∀ x ∈ Icc 0 cutoff, Real.sqrt (1 - x ^ 2) ≠ 0 := by
intro x hx
apply ne_of_gt (Real.sqrt_pos.2 _)
have hxl : x < 1 := lt_of_le_of_lt hx.2 cutoff_lt_one
nlinarith [hx.1, sq_nonneg x]
exact (continuousOn_const.sub (continuousOn_const.mul (continuousOn_id.pow 2))).div
((Real.continuous_sqrt.comp (continuous_const.sub (continuous_id.pow 2))).continuousOn) hs
lemma antitoneOn_rawWeight : AntitoneOn rawWeight (Icc 0 cutoff) := by
refine antitoneOn_of_hasDerivWithinAt_nonpos (f' := fun x =>
x * (49 * x ^ 2 - 48) / (50 * Real.sqrt (1 - x ^ 2) ^ 3))
(convex_Icc 0 cutoff) continuousOn_rawWeight ?_ ?_
· intro x hx
rw [interior_Icc] at hx
exact (hasDerivAt_rawWeight ⟨hx.1, lt_trans hx.2 cutoff_lt_one⟩).hasDerivWithinAt
· intro x hx
rw [interior_Icc] at hx
apply div_nonpos_of_nonpos_of_nonneg _ (by positivity)
apply mul_nonpos_of_nonneg_of_nonpos (le_of_lt hx.1)
have hsq : x ^ 2 ≤ cutoff ^ 2 :=
pow_le_pow_left₀ (le_of_lt hx.1) (le_of_lt hx.2) 2
nlinarith [cutoff_sq]
lemma weight_mem {x : ℝ} (hx : 0 ≤ x) : weight x ∈ Icc ell 1 := by
have hm : min x cutoff ∈ Icc 0 cutoff :=
⟨le_min hx (le_of_lt cutoff_pos), min_le_right _ _⟩
constructor
· exact rawWeight_lower ⟨hm.1, lt_of_le_of_lt hm.2 cutoff_lt_one⟩
· have hh := antitoneOn_rawWeight ⟨le_rfl, le_of_lt cutoff_pos⟩ hm hm.1
simpa [weight, rawWeight] using hh
lemma antitoneOn_weight : AntitoneOn weight (Ici 0) := by
intro x hx y hy hxy
exact antitoneOn_rawWeight
⟨le_min hx (le_of_lt cutoff_pos), min_le_right _ _⟩
⟨le_min hy (le_of_lt cutoff_pos), min_le_right _ _⟩ (min_le_min hxy le_rfl)
lemma weight_le_rawWeight {x : ℝ} (hx : x ∈ Ico 0 1) : weight x ≤ rawWeight x := by
by_cases hxc : x ≤ cutoff
· simp [weight, min_eq_left hxc]
· rw [weight, min_eq_right (le_of_not_ge hxc), rawWeight_cutoff]
exact rawWeight_lower hx
lemma fluxAux_weight_nonneg {m : ℝ} (hm : m ∈ Ioc 0 1) :
0 ≤ fluxAux (weight m) m := by
rcases lt_or_eq_of_le hm.2 with hm1 | rfl
· have hs : 0 < Real.sqrt (1 - m ^ 2) := sqrt_pos_of_mem_Ioo ⟨hm.1, hm1⟩
have hw := weight_le_rawWeight ⟨le_of_lt hm.1, hm1⟩
have hh : weight m * Real.sqrt (1 - m ^ 2) ≤ 1 - lambda * m ^ 2 :=
(le_div_iff₀ hs).mp hw
rw [fluxAux, show 1 / m - lambda * m - weight m * (Real.sqrt (1 - m ^ 2) / m) =
(1 - lambda * m ^ 2 - weight m * Real.sqrt (1 - m ^ 2)) / m by
field_simp]
exact div_nonneg (sub_nonneg.mpr hh) (le_of_lt hm.1)
· norm_num [fluxAux, lambda]
theorem integrated_flux_probability {Ω : Type*} [MeasurableSpace Ω]
{μ : Measure Ω} [IsProbabilityMeasure μ] {α : Ω → ℝ} {ε : ℝ}
(hε : 0 < ε) (hα : ∀ᵐ x ∂μ, α x ∈ Icc ε 1)
(hαi : Integrable α μ) (hii : Integrable (fun x => 1 / α x) μ)
(hqi : Integrable (fun x => Real.sqrt (1 - α x ^ 2) / α x) μ) :
weight (∫ x, α x ∂μ) * (∫ x, Real.sqrt (1 - α x ^ 2) / α x ∂μ) ≤
(∫ x, 1 / α x ∂μ) - lambda * (∫ x, α x ∂μ) := by
let m : ℝ := ∫ x, α x ∂μ
have hm : m ∈ Icc ε 1 := by
constructor
· have hh := integral_mono_ae (integrable_const ε) hαi (hα.mono fun _ hx => hx.1)
simpa [m] using hh
· have hh := integral_mono_ae hαi (integrable_const (1 : ℝ)) (hα.mono fun _ hx => hx.2)
simpa [m] using hh
have hm0 : 0 < m := lt_of_lt_of_le hε hm.1
have hw := weight_mem (le_of_lt hm0)
have hJ : weight m ∈ Icc 0 1 := ⟨le_trans (by norm_num [ell]) hw.1, hw.2⟩
have hfi : Integrable ((fluxAux (weight m)) ∘ α) μ :=
(hii.sub (hαi.const_mul lambda)).sub (hqi.const_mul (weight m))
have hj := (convexOn_fluxAux hε hJ).map_integral_le
(continuousOn_fluxAux hε (weight m)) isClosed_Icc hα hαi hfi
have hh : 0 ≤ ∫ x, fluxAux (weight m) (α x) ∂μ :=
(fluxAux_weight_nonneg ⟨hm0, hm.2⟩).trans hj
change 0 ≤ ∫ x, ((1 / α x - lambda * α x) -
weight m * (Real.sqrt (1 - α x ^ 2) / α x)) ∂μ at hh
have hli : Integrable (fun x => 1 / α x - lambda * α x) μ :=
hii.sub (hαi.const_mul lambda)
rw [integral_sub hli (hqi.const_mul (weight m)),
integral_sub hii (hαi.const_mul lambda), integral_const_mul, integral_const_mul] at hh
exact sub_nonneg.mp hh
lemma product_sqrt_le_half {x : ℝ} (hx : x ∈ Icc 0 1) :
x * Real.sqrt (1 - x ^ 2) ≤ 1 / 2 := by
have hr : 0 ≤ 1 - x ^ 2 := by nlinarith [hx.1, hx.2]
nlinarith [Real.sq_sqrt hr, sq_nonneg (x - Real.sqrt (1 - x ^ 2))]
lemma product_sqrt_le_of_lower {a x d : ℝ} (ha : 0 ≤ a) (hax : a ≤ x)
(hx1 : x ≤ 1) (ha2 : 1 / 2 ≤ a ^ 2) (hd : 0 ≤ d)
(had : a ^ 2 * (1 - a ^ 2) ≤ d ^ 2) :
x * Real.sqrt (1 - x ^ 2) ≤ d := by
have hx0 := le_trans ha hax
have hxa := pow_le_pow_left₀ ha hax 2
have hr : 0 ≤ 1 - x ^ 2 := by nlinarith
have hs := Real.sq_sqrt hr
have hxs := congrArg (fun t : ℝ => x ^ 2 * t) hs
have hp : (x ^ 2 - a ^ 2) * (1 - a ^ 2 - x ^ 2) ≤ 0 :=
mul_nonpos_of_nonneg_of_nonpos (by linarith) (by nlinarith)
apply (sq_le_sq₀ (mul_nonneg hx0 (Real.sqrt_nonneg _)) hd).1
nlinarith
lemma weight_derivative_bound_of_row {x n d : ℝ} (hx : x ∈ Ico 0 1)
(hn : n * (1 - x ^ 2) ≤ 48 / 100 - (49 / 100 : ℝ) * x ^ 2)
(hd : x * Real.sqrt (1 - x ^ 2) ≤ d) (hnd : (91 / 100 : ℝ) * d ≤ n) :
(91 / 100 : ℝ) * x ≤
(48 / 100 - (49 / 100 : ℝ) * x ^ 2) / Real.sqrt (1 - x ^ 2) ^ 3 := by
have hr : 0 < 1 - x ^ 2 := by nlinarith [hx.1, hx.2]
have hs : 0 < Real.sqrt (1 - x ^ 2) := Real.sqrt_pos.2 hr
apply (le_div_iff₀ (pow_pos hs 3)).2
calc
(91 / 100 : ℝ) * x * Real.sqrt (1 - x ^ 2) ^ 3 =
((91 / 100 : ℝ) * (x * Real.sqrt (1 - x ^ 2))) * Real.sqrt (1 - x ^ 2) ^ 2 := by ring
_ ≤ ((91 / 100 : ℝ) * d) * Real.sqrt (1 - x ^ 2) ^ 2 :=
mul_le_mul_of_nonneg_right (mul_le_mul_of_nonneg_left hd (by norm_num)) (sq_nonneg _)
_ ≤ n * Real.sqrt (1 - x ^ 2) ^ 2 := mul_le_mul_of_nonneg_right hnd (sq_nonneg _)
_ = n * (1 - x ^ 2) := by rw [Real.sq_sqrt (le_of_lt hr)]
_ ≤ 48 / 100 - (49 / 100 : ℝ) * x ^ 2 := hn
theorem weight_derivative_bound {x : ℝ} (hx : x ∈ Icc 0 (24 / 25 : ℝ)) :
(91 / 100 : ℝ) * x ≤
(48 / 100 - (49 / 100 : ℝ) * x ^ 2) / Real.sqrt (1 - x ^ 2) ^ 3 := by
have hx1 : x ∈ Ico 0 1 := ⟨hx.1, by linarith [hx.2]⟩
by_cases h84 : x ≤ 84 / 100
· have hsq := pow_le_pow_left₀ hx.1 h84 2
apply weight_derivative_bound_of_row (n := 456 / 1000) (d := 1 / 2) hx1
· nlinarith
· exact product_sqrt_le_half ⟨hx.1, le_of_lt hx1.2⟩
· norm_num
by_cases h89 : x ≤ 89 / 100
· have hsq := pow_le_pow_left₀ hx.1 h89 2
apply weight_derivative_bound_of_row (n := 44 / 100) (d := 46 / 100) hx1
· nlinarith
· apply product_sqrt_le_of_lower (a := 84 / 100) (by norm_num) (le_of_not_ge h84)
(le_of_lt hx1.2) <;> norm_num
· norm_num
by_cases h94 : x ≤ 94 / 100
· have hsq := pow_le_pow_left₀ hx.1 h94 2
apply weight_derivative_bound_of_row (n := 40 / 100) (d := 41 / 100) hx1
· nlinarith
· apply product_sqrt_le_of_lower (a := 89 / 100) (by norm_num) (le_of_not_ge h89)
(le_of_lt hx1.2) <;> norm_num
· norm_num
· have hsq := pow_le_pow_left₀ hx.1 hx.2 2
apply weight_derivative_bound_of_row (n := 36 / 100) (d := 33 / 100) hx1
· nlinarith
· apply product_sqrt_le_of_lower (a := 94 / 100) (by norm_num) (le_of_not_ge h94)
(le_of_lt hx1.2) <;> norm_num
· norm_num
def squaredWeight (r : ℝ) : ℝ := (1 - lambda * r) / Real.sqrt (1 - r)
lemma hasDerivAt_squaredWeight {r : ℝ} (hr : r < 1) :
HasDerivAt squaredWeight
(-((48 / 100 - (49 / 100 : ℝ) * r) / Real.sqrt (1 - r) ^ 3)) r := by
have hrad : 0 < 1 - r := sub_pos.2 hr
have hs := ((hasDerivAt_const r (1 : ℝ)).sub (hasDerivAt_id r)).sqrt (ne_of_gt hrad)
have hs2 := Real.sq_sqrt (le_of_lt hrad)
have hs0 := ne_of_gt (Real.sqrt_pos.2 hrad)
have hh := ((hasDerivAt_const r (1 : ℝ)).sub
((hasDerivAt_id r).const_mul lambda)).div hs hs0
convert hh using 1 <;> try rfl
dsimp [lambda]
field_simp
linear_combination 9800 * hs2
lemma squaredWeight_eq_rawWeight {r : ℝ} (hr : 0 ≤ r) :
squaredWeight r = rawWeight (Real.sqrt r) := by
simp only [squaredWeight, rawWeight, Real.sq_sqrt hr]
lemma squaredWeight_difference {a b : ℝ} (ha : 0 ≤ a) (hab : a ≤ b)
(hb : b ≤ (24 / 25 : ℝ) ^ 2) :
(91 / 100 : ℝ) * Real.sqrt a * (b - a) ≤ squaredWeight a - squaredWeight b := by
have hi : ∀ r ∈ Icc a b, 0 ≤ r ∧ r < 1 := fun r hr => ⟨le_trans ha hr.1, by linarith [hr.2]⟩
have hc : ContinuousOn squaredWeight (Icc a b) := by
intro r hr
exact (hasDerivAt_squaredWeight (hi r hr).2).continuousAt.continuousWithinAt
have hm : AntitoneOn (fun r => squaredWeight r + (91 / 100 : ℝ) * Real.sqrt a * r) (Icc a b) := by
apply antitoneOn_of_hasDerivWithinAt_nonpos (f' := fun r =>
-((48 / 100 - (49 / 100 : ℝ) * r) / Real.sqrt (1 - r) ^ 3) +
(91 / 100 : ℝ) * Real.sqrt a) (convex_Icc a b)
· exact hc.add (continuousOn_const.mul continuousOn_id)
· intro r hr
rw [interior_Icc] at hr
convert ((hasDerivAt_squaredWeight (hi r ⟨le_of_lt hr.1, le_of_lt hr.2⟩).2).add
((hasDerivAt_id r).const_mul ((91 / 100 : ℝ) * Real.sqrt a))).hasDerivWithinAt using 1 <;> try rfl
simp only [mul_one]
· intro r hr
rw [interior_Icc] at hr
have hr0 := le_trans ha (le_of_lt hr.1)
have hs : Real.sqrt r ∈ Icc 0 (24 / 25 : ℝ) :=
⟨Real.sqrt_nonneg _, Real.sqrt_le_iff.2 ⟨by norm_num, le_trans (le_of_lt hr.2) hb⟩⟩
have hbound := weight_derivative_bound hs
rw [Real.sq_sqrt hr0] at hbound
have hmon := Real.sqrt_le_sqrt (le_of_lt hr.1)
linarith
have hh := hm ⟨le_refl a, hab⟩ ⟨hab, le_refl b⟩ hab
linarith
theorem pointwise_weight_gain {x K : ℝ} (hx : x ∈ Icc 0 (24 / 25 : ℝ)) (hK : 0 ≤ K) :
(91 / 100 : ℝ) * x ^ 3 * K / Real.sqrt (1 + K) ^ 3 ≤
weight (x / Real.sqrt (1 + K)) - weight x := by
have hp : 0 < 1 + K := by linarith
have hs0 : 0 < Real.sqrt (1 + K) := Real.sqrt_pos.2 hp
have hs1 : 1 ≤ Real.sqrt (1 + K) := by
nlinarith [Real.sq_sqrt (le_of_lt hp), Real.sqrt_nonneg (1 + K)]
have hy0 : 0 ≤ x / Real.sqrt (1 + K) := div_nonneg hx.1 (le_of_lt hs0)
have hyx : x / Real.sqrt (1 + K) ≤ x := (div_le_iff₀ hs0).2 (by nlinarith [hx.1])
have hd : (24 / 25 : ℝ) < cutoff := by nlinarith [cutoff_sq, cutoff_pos]
have hc1 : x ≤ cutoff := le_trans hx.2 (le_of_lt hd)
have hc2 : x / Real.sqrt (1 + K) ≤ cutoff := le_trans hyx hc1
rw [weight, min_eq_left hc2, weight, min_eq_left hc1]
have ha : 0 ≤ x ^ 2 / (1 + K) := div_nonneg (sq_nonneg x) (le_of_lt hp)
have hab : x ^ 2 / (1 + K) ≤ x ^ 2 := (div_le_iff₀ hp).2 (by nlinarith [sq_nonneg x])
have hb := pow_le_pow_left₀ hx.1 hx.2 2
have hg := squaredWeight_difference ha hab hb
have heqa : Real.sqrt (x ^ 2 / (1 + K)) = x / Real.sqrt (1 + K) := by
rw [Real.sqrt_div (sq_nonneg x), Real.sqrt_sq hx.1]
rw [squaredWeight_eq_rawWeight ha, squaredWeight_eq_rawWeight (sq_nonneg x),
heqa, Real.sqrt_sq hx.1] at hg
convert hg using 1
have hs2 := Real.sq_sqrt (le_of_lt hp)
field_simp
linear_combination -x ^ 3 * K * hs2
end CubicTorus.Nesting
noncomputable section
open Set MeasureTheory
open scoped Interval
namespace CubicTorus.Shape
def t (h : ℝ) : ℝ := 2 / (1 + Real.sqrt (1 + 4 * h ^ 2 / Real.pi))
def c : ℝ := 27 / 10
def dm : ℝ := 21 / 100
def u (h : ℝ) : ℝ := min (1 - 1 / Real.pi) ((24 / 25 : ℝ) / h)
def theta : ℝ := 2 / (1 + Real.sqrt (1 + 4 * c * dm / Real.pi))
def shape (q : ℝ) : ℝ := min (q ^ 2) (Real.pi * (1 - q) / (c * dm))
def moment : ℝ := ∫ q in (0 : ℝ)..1, shape q
def firstMoment : ℝ := ∫ q in (0 : ℝ)..1, q * shape q
def meanQ : ℝ := firstMoment / moment
def p₂ : ℝ := 1 + c * dm ^ 2 * theta ^ 2
lemma positive_quadratic_root {a : ℝ} (ha : 0 < a) :
let r := 2 / (1 + Real.sqrt (1 + 4 * a / Real.pi))
0 < r ∧ r < 1 ∧ a * r ^ 2 = Real.pi * (1 - r) := by
have hp := Real.pi_pos
have hr : 1 < 1 + 4 * a / Real.pi := by
have : 0 < 4 * a / Real.pi := by positivity
linarith
have hs0 := Real.sqrt_nonneg (1 + 4 * a / Real.pi)
have hs := Real.sq_sqrt (by linarith : 0 ≤ 1 + 4 * a / Real.pi)
have hs1 : 1 < Real.sqrt (1 + 4 * a / Real.pi) := by nlinarith
have hd : 0 < 1 + Real.sqrt (1 + 4 * a / Real.pi) := by linarith
refine ⟨div_pos (by norm_num) hd, (div_lt_one hd).2 (by linarith), ?_⟩
generalize hz : Real.sqrt (1 + 4 * a / Real.pi) = z at *
field_simp at hs ⊢
nlinarith
lemma t_spec {h : ℝ} (hh : 0 < h) :
0 < t h ∧ t h < 1 ∧ h ^ 2 * t h ^ 2 = Real.pi * (1 - t h) := by
exact positive_quadratic_root (sq_pos_of_pos hh)
lemma extent_lower_bound {h s L : ℝ} (hL : 0 < L)
(hcal : (1 - s) / L + Real.pi * L / 4 ≤ h * s) :
2 / Real.pi * (h * s - Real.sqrt (h ^ 2 * s ^ 2 - Real.pi * (1 - s))) ≤ L := by
have hp := Real.pi_pos
have hh := (mul_le_mul_of_nonneg_right hcal (le_of_lt hL))
have hsq : (h * s - Real.pi * L / 2) ^ 2 ≤ h ^ 2 * s ^ 2 - Real.pi * (1 - s) := by
have heq : ((1 - s) / L + Real.pi * L / 4) * L = 1 - s + Real.pi * L ^ 2 / 4 := by
field_simp
rw [heq] at hh
have hm := mul_le_mul_of_nonneg_left hh (le_of_lt hp)
nlinarith
have hs := Real.le_sqrt_of_sq_le hsq
convert (show 2 * (h * s - Real.sqrt (h ^ 2 * s ^ 2 - Real.pi * (1 - s))) / Real.pi ≤ L from
(div_le_iff₀ hp).2 (by nlinarith)) using 1
ring
lemma endpoint_slack_bound {h s t₀ : ℝ} (hh : 0 ≤ h) (ht : 0 ≤ t₀) (hst : t₀ ≤ s)
(hroot : h ^ 2 * t₀ ^ 2 = Real.pi * (1 - t₀)) :
1 - 2 / Real.pi * (h * s - Real.sqrt (h ^ 2 * s ^ 2 - Real.pi * (1 - s))) ≤
1 - 2 * h * t₀ / Real.pi +
(2 / Real.pi * Real.sqrt (Real.pi + 2 * h ^ 2 * t₀)) * Real.sqrt (s - t₀) := by
let Y := Real.sqrt (s - t₀)
let R := Real.sqrt (Real.pi + 2 * h ^ 2 * t₀)
have hY : 0 ≤ Y := Real.sqrt_nonneg _
have hY2 : Y ^ 2 = s - t₀ := Real.sq_sqrt (sub_nonneg.2 hst)
have hR : 0 ≤ R := Real.sqrt_nonneg _
have hR2 : R ^ 2 = Real.pi + 2 * h ^ 2 * t₀ := Real.sq_sqrt (by positivity)
have hupper : Real.sqrt (h ^ 2 * s ^ 2 - Real.pi * (1 - s)) ≤ R * Y + h * Y ^ 2 := by
apply Real.sqrt_le_iff.2
refine ⟨by positivity, ?_⟩
have hm : 0 ≤ 2 * (R * Y) * (h * Y ^ 2) := by positivity
have heq : h ^ 2 * s ^ 2 - Real.pi * (1 - s) = R ^ 2 * Y ^ 2 + h ^ 2 * Y ^ 4 := by
rw [hR2]
have hs : s = t₀ + Y ^ 2 := by linarith
rw [hs]
nlinarith [hroot]
rw [heq]
nlinarith
have hm := mul_le_mul_of_nonneg_left hupper (le_of_lt (div_pos (by norm_num : (0 : ℝ) < 2) Real.pi_pos))
dsimp [R, Y] at hm hY2
rw [hY2] at hm
ring_nf at hm ⊢
linarith only [hm]
theorem interval_placement {h : ℝ} (hh : h ∈ Icc (51 / 50 : ℝ) (81 / 50 : ℝ)) :
(1033 / 2700 : ℝ) ≤ u h - dm ∧ (38 / 100 : ℝ) < u h - dm ∧
1 / Real.pi < (38 / 100 : ℝ) ∧ u h ≤ 1 - 1 / Real.pi ∧
u h < t h ∧ h * u h ≤ 24 / 25 := by
have hp := Real.pi_pos
have hp3 := Real.pi_gt_three
have hh0 : 0 < h := by linarith [hh.1]
have hu1 : u h ≤ 1 - 1 / Real.pi := min_le_left _ _
have huv : u h ≤ (24 / 25 : ℝ) / h := min_le_right _ _
have hu : (16 / 27 : ℝ) ≤ u h := by
apply le_min
· apply (le_sub_iff_add_le).2
have hip : 1 / Real.pi ≤ (1 / 3 : ℝ) := (div_le_div_of_nonneg_left (by norm_num) (by norm_num) (le_of_lt hp3))
linarith
· apply (le_div_iff₀ hh0).2
linarith [hh.2]
have hhU : h * u h ≤ 24 / 25 := by
have := (le_div_iff₀ hh0).1 huv
nlinarith
have htr := t_spec hh0
have hlt : u h < t h := by
by_contra! hn
have hm := mul_le_mul_of_nonneg_left (pow_le_pow_left₀ (le_of_lt htr.1) hn 2) (sq_nonneg h)
have hsq := pow_le_pow_left₀ (mul_nonneg (le_of_lt hh0) (by linarith : 0 ≤ u h)) hhU 2
have hip : 1 ≤ Real.pi * (1 - u h) := by
have hh := mul_le_mul_of_nonneg_left hu1 (le_of_lt hp)
field_simp at hh
nlinarith
nlinarith [htr.2.2]
refine ⟨?_, ?_, ?_, hu1, hlt, hhU⟩
· dsimp [dm]; linarith
· dsimp [dm]; linarith
· apply (div_lt_iff₀ hp).2
nlinarith
lemma theta_spec : 0 < theta ∧ theta < 1 ∧ c * dm * theta ^ 2 = Real.pi * (1 - theta) := by
simpa only [theta, mul_assoc] using positive_quadratic_root (a := c * dm) (by norm_num [c, dm])
lemma theta_bounds : (32 / 37 : ℝ) < theta ∧ theta < 13 / 15 := by
have ht := theta_spec
have hp := Real.pi_gt_d2
have hpU : Real.pi < (22 / 7 : ℝ) := by linarith [Real.pi_lt_d4]
have hr := ht.2.2
norm_num [c, dm] at hr
constructor
· by_contra! hn
have hs := pow_le_pow_left₀ (le_of_lt ht.1) hn 2
have hh := mul_lt_mul_of_pos_right hp (by linarith : 0 < 1 - theta)
nlinarith
· by_contra! hn
have hs := pow_le_pow_left₀ (by norm_num : (0 : ℝ) ≤ 13 / 15) hn 2
have hh := mul_lt_mul_of_pos_right hpU (by linarith : 0 < 1 - theta)
nlinarith
lemma shape_on_left {q : ℝ} (hq : q ∈ Icc 0 theta) : shape q = q ^ 2 := by
apply min_eq_left
apply (le_div_iff₀ (by norm_num [c, dm] : 0 < c * dm)).2
have hm := mul_le_mul_of_nonneg_left (pow_le_pow_left₀ hq.1 hq.2 2)
(by norm_num [c, dm] : 0 ≤ c * dm)
have ht := theta_spec.2.2
have hp := mul_le_mul_of_nonneg_left hq.2 (le_of_lt Real.pi_pos)
nlinarith
lemma shape_on_right {q : ℝ} (hq : q ∈ Icc theta 1) :
shape q = Real.pi * (1 - q) / (c * dm) := by
apply min_eq_right
apply (div_le_iff₀ (by norm_num [c, dm] : 0 < c * dm)).2
have hm := mul_le_mul_of_nonneg_left (pow_le_pow_left₀ (le_of_lt theta_spec.1) hq.1 2)
(by norm_num [c, dm] : 0 ≤ c * dm)
have ht := theta_spec.2.2
have hp := mul_le_mul_of_nonneg_left hq.1 (le_of_lt Real.pi_pos)
nlinarith
lemma shape_nonneg {q : ℝ} (hq : q ∈ Icc 0 1) : 0 ≤ shape q := by
exact le_min (sq_nonneg q) (div_nonneg
(mul_nonneg (le_of_lt Real.pi_pos) (sub_nonneg.2 hq.2)) (by norm_num [c, dm]))
lemma shape_le_one {q : ℝ} (hq : q ∈ Icc 0 1) : shape q ≤ 1 := by
have hq2 := pow_le_pow_left₀ hq.1 hq.2 2
exact le_trans (min_le_left _ _) (by simpa using hq2)
lemma shape_max {q : ℝ} (hq : q ∈ Icc 0 1) : shape q ≤ theta ^ 2 := by
by_cases hh : q ≤ theta
· rw [shape_on_left ⟨hq.1, hh⟩]
exact pow_le_pow_left₀ hq.1 hh 2
· rw [shape_on_right ⟨le_of_not_ge hh, hq.2⟩]
apply (div_le_iff₀ (by norm_num [c, dm] : 0 < c * dm)).2
have ht := theta_spec.2.2
have hp := mul_le_mul_of_nonneg_left (le_of_not_ge hh) (le_of_lt Real.pi_pos)
nlinarith
lemma continuous_shape : Continuous shape := by
unfold shape
fun_prop
lemma integral_eq_split : moment = theta ^ 3 / 3 +
Real.pi / (c * dm) * (1 - theta) ^ 2 / 2 := by
have hfi : IntervalIntegrable shape volume 0 theta := continuous_shape.intervalIntegrable 0 theta
have hfi2 : IntervalIntegrable shape volume theta 1 := continuous_shape.intervalIntegrable theta 1
have h0 := theta_spec
unfold moment
rw [← intervalIntegral.integral_add_adjacent_intervals hfi hfi2]
have hleft : (∫ q in (0 : ℝ)..theta, shape q) = theta ^ 3 / 3 := by
rw [intervalIntegral.integral_congr (g := fun q : ℝ => q ^ 2) ?_]
· norm_num
· intro q hq
rw [uIcc_of_le (le_of_lt h0.1)] at hq
exact shape_on_left hq
have hright : (∫ q in theta..(1 : ℝ), shape q) =
Real.pi / (c * dm) * (1 - theta) ^ 2 / 2 := by
rw [intervalIntegral.integral_congr (g := fun q : ℝ => Real.pi / (c * dm) * (1 - q)) ?_]
· rw [intervalIntegral.integral_const_mul,
intervalIntegral.integral_sub
(show IntervalIntegrable (fun _ : ℝ => (1 : ℝ)) volume theta 1 from continuous_const.intervalIntegrable _ _)
(show IntervalIntegrable (fun q : ℝ => q) volume theta 1 from continuous_id.intervalIntegrable _ _)]
norm_num
ring
· intro q hq
rw [uIcc_of_le (le_of_lt h0.2.1)] at hq
dsimp only
rw [shape_on_right hq]
ring
rw [hleft, hright]
lemma moment_eq : moment = theta ^ 2 * (3 - theta) / 6 := by
rw [integral_eq_split]
have ht := theta_spec.2.2
norm_num [c, dm] at ht ⊢
linear_combination -(500 / 567 : ℝ) * (1 - theta) * ht
lemma firstMoment_eq : firstMoment = theta ^ 2 * (2 + 2 * theta - theta ^ 2) / 12 := by
have hc : Continuous (fun q : ℝ => q * shape q) := continuous_id.mul continuous_shape
have h0 := theta_spec
unfold firstMoment
rw [← intervalIntegral.integral_add_adjacent_intervals
(hc.intervalIntegrable (0 : ℝ) theta) (hc.intervalIntegrable theta (1 : ℝ))]
have hl : (∫ q in (0 : ℝ)..theta, q * shape q) = theta ^ 4 / 4 := by
rw [intervalIntegral.integral_congr (g := fun q : ℝ => q ^ 3) ?_]
· norm_num
· intro q hq
rw [uIcc_of_le (le_of_lt h0.1)] at hq
dsimp only
rw [shape_on_left hq]
ring
have hr : (∫ q in theta..(1 : ℝ), q * shape q) =
Real.pi / (c * dm) * ((1 - theta ^ 2) / 2 - (1 - theta ^ 3) / 3) := by
rw [intervalIntegral.integral_congr (g := fun q : ℝ => Real.pi / (c * dm) * (q - q ^ 2)) ?_]
· rw [intervalIntegral.integral_const_mul,
intervalIntegral.integral_sub
(show IntervalIntegrable (fun q : ℝ => q) volume theta 1 from continuous_id.intervalIntegrable _ _)
(show IntervalIntegrable (fun q : ℝ => q ^ 2) volume theta 1 from (continuous_id.pow 2).intervalIntegrable _ _)]
norm_num
· intro q hq
rw [uIcc_of_le (le_of_lt h0.2.1)] at hq
dsimp only
rw [shape_on_right hq]
ring
rw [hl, hr]
have ht := h0.2.2
norm_num [c, dm] at ht ⊢
linear_combination -(500 / 1701 : ℝ) * (1 - theta) * (1 + 2 * theta) * ht
lemma moment_pos : 0 < moment := by
rw [moment_eq]
have ht := theta_spec
have h3 : 0 < 3 - theta := by linarith [ht.2.1]
have htpos := ht.1
positivity
lemma meanQ_eq : meanQ = (2 + 2 * theta - theta ^ 2) / (2 * (3 - theta)) := by
unfold meanQ
rw [moment_eq, firstMoment_eq]
have ht := theta_spec
have ht0 := ne_of_gt ht.1
have h30 : 3 - theta ≠ 0 := by linarith [ht.2.1]
field_simp [ht0, h30]
ring
lemma meanQ_mem : meanQ ∈ Ioo 0 1 := by
rw [meanQ_eq]
have ht := theta_spec
have hs : theta ^ 2 < 1 := by nlinarith [ht.1, ht.2.1]
constructor
· apply div_pos
· nlinarith
· linarith
· apply (div_lt_one (by linarith : 0 < 2 * (3 - theta))).2
nlinarith [sq_nonneg (theta - 2)]
theorem moment_bounds : (2659 / 10000 : ℝ) < moment ∧
(697 / 1000 : ℝ) < meanQ ∧ p₂ < (109 / 100 : ℝ) := by
have ht := theta_spec
have hb := theta_bounds
have hθ2 := pow_lt_pow_left₀ hb.1 (by norm_num : (0 : ℝ) ≤ 32 / 37) (by norm_num : (2 : ℕ) ≠ 0)
have hθU := pow_lt_pow_left₀ hb.2 (le_of_lt ht.1) (by norm_num : (2 : ℕ) ≠ 0)
refine ⟨?_, ?_, ?_⟩
· rw [moment_eq]
have hm : 0 ≤ (theta ^ 2 - (32 / 37) ^ 2) * (3 - theta) :=
mul_nonneg (by linarith) (by linarith [ht.2.1])
nlinarith [hb.2]
· rw [meanQ_eq]
apply (lt_div_iff₀ (by linarith : 0 < 2 * (3 - theta))).2
nlinarith [sq_nonneg (theta - 1)]
· dsimp [p₂, c, dm]
nlinarith
lemma affine_shape_integral (a b : ℝ) :
(∫ q in (0 : ℝ)..1, (a + b * q) * shape q) = moment * (a + b * meanQ) := by
have hc : IntervalIntegrable shape volume 0 1 := continuous_shape.intervalIntegrable 0 1
have hq : IntervalIntegrable (fun q : ℝ => q * shape q) volume 0 1 :=
(continuous_id.mul continuous_shape).intervalIntegrable 0 1
have heq : (fun q : ℝ => (a + b * q) * shape q) =
fun q => a * shape q + b * (q * shape q) := by funext q; ring
rw [heq, intervalIntegral.integral_add (hc.const_mul a) (hq.const_mul b),
intervalIntegral.integral_const_mul, intervalIntegral.integral_const_mul]
change a * moment + b * firstMoment = moment * (a + b * meanQ)
unfold meanQ
field_simp [ne_of_gt moment_pos]
lemma cubic_shape_lower {a b : ℝ} (ha : 0 ≤ a) (hb : 0 ≤ b) :
moment * (a + b * meanQ) ^ 3 ≤
∫ q in (0 : ℝ)..1, (a + b * q) ^ 3 * shape q := by
let m := a + b * meanQ
have hm : 0 ≤ m := add_nonneg ha (mul_nonneg hb (le_of_lt meanQ_mem.1))
have hc : IntervalIntegrable (fun q : ℝ => (a + b * q) ^ 3 * shape q) volume 0 1 :=
(((continuous_const.add (continuous_const.mul continuous_id)).pow 3).mul continuous_shape).intervalIntegrable 0 1
have h1 : IntervalIntegrable (fun q : ℝ => m ^ 3 * shape q) volume 0 1 :=
(continuous_const.mul continuous_shape).intervalIntegrable 0 1
have h2 : IntervalIntegrable (fun q : ℝ => (a + b * q - m) * shape q) volume 0 1 :=
(( (continuous_const.add (continuous_const.mul continuous_id)).sub continuous_const).mul continuous_shape).intervalIntegrable 0 1
have hbound := intervalIntegral.integral_mono_on (show (0 : ℝ) ≤ 1 by norm_num)
(h1.add (h2.const_mul (3 * m ^ 2))) hc (fun q hq => by
have hs := shape_nonneg hq
have hf : 0 ≤ a + b * q := add_nonneg ha (mul_nonneg hb hq.1)
have hh := mul_nonneg (mul_nonneg (sq_nonneg (a + b * q - m))
(show 0 ≤ a + b * q + 2 * m by linarith)) hs
nlinarith)
rw [intervalIntegral.integral_add h1 (h2.const_mul (3 * m ^ 2)),
intervalIntegral.integral_const_mul, intervalIntegral.integral_const_mul] at hbound
have hz : (∫ q in (0 : ℝ)..1, (a + b * q - m) * shape q) = 0 := by
have heq : (fun q : ℝ => (a + b * q - m) * shape q) =
fun q => (a - m + b * q) * shape q := by funext q; ring
rw [heq, affine_shape_integral]
dsimp [m]
ring
rw [hz, mul_zero, add_zero] at hbound
change moment * m ^ 3 ≤ _
change m ^ 3 * moment ≤ _ at hbound
linarith only [hbound]
lemma cubic_shape_lower_dm {u₀ δ : ℝ} (hδ : δ ∈ Icc 0 dm) (hu : dm ≤ u₀) :
moment * (u₀ - (1 - meanQ) * dm) ^ 3 ≤
∫ q in (0 : ℝ)..1, (u₀ - δ + δ * q) ^ 3 * shape q := by
have hm := meanQ_mem
have h1 := cubic_shape_lower (a := u₀ - δ) (b := δ) (by linarith [hδ.2]) hδ.1
apply le_trans _ h1
apply mul_le_mul_of_nonneg_left _ (le_of_lt moment_pos)
have hb : u₀ - (1 - meanQ) * dm ≤ u₀ - δ + δ * meanQ := by
have hh := mul_le_mul_of_nonneg_left hδ.2 (show 0 ≤ 1 - meanQ by linarith [hm.2])
nlinarith
apply pow_le_pow_left₀ _ hb 3
have hh : 0 ≤ dm * meanQ := mul_nonneg (by norm_num [dm]) (le_of_lt hm.1)
nlinarith
lemma p₂_pos : 0 < p₂ := by
unfold p₂ c dm
positivity
lemma coefficient_lower : (574 / 1000 : ℝ) <
((91 / 100 : ℝ) * c * moment) / Real.sqrt p₂ ^ 3 := by
have hM := moment_bounds.1
have hp := moment_bounds.2.2
have hs : 0 < Real.sqrt p₂ := Real.sqrt_pos.2 p₂_pos
have hs2 := Real.sq_sqrt (le_of_lt p₂_pos)
have hd : (Real.sqrt p₂ ^ 3) ^ 2 = p₂ ^ 3 := by
rw [show (Real.sqrt p₂ ^ 3) ^ 2 = (Real.sqrt p₂ ^ 2) ^ 3 by ring, hs2]
have hp3 := pow_lt_pow_left₀ hp (le_of_lt p₂_pos) (by norm_num : (3 : ℕ) ≠ 0)
have hc : (574 / 1000 : ℝ) * Real.sqrt p₂ ^ 3 <
(91 / 100 : ℝ) * c * (2659 / 10000 : ℝ) := by
apply (sq_lt_sq₀ (by positivity)
(by norm_num [c] : (0 : ℝ) ≤ (91 / 100 : ℝ) * c * (2659 / 10000 : ℝ))).1
rw [mul_pow, hd]
norm_num [c]
nlinarith only [hp3]
apply (lt_div_iff₀ (pow_pos hs 3)).2
have hmc := mul_lt_mul_of_pos_left hM (by norm_num [c] : (0 : ℝ) < (91 / 100 : ℝ) * c)
exact lt_trans hc hmc
end CubicTorus.Shape
end
end
end
end
end OAI