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import OAI.Geometry.LatticeCovering.Rates
namespace OAI
section
section
noncomputable section
namespace SingleLatticeCovering.Horizontal
open MeasureTheory Completion
open scoped ENNReal BigOperators
structure FullLattice (m : ℕ) where
module : Submodule ℤ (Fin m → ℝ)
discrete : DiscreteTopology module
full : IsZLattice ℝ module
attribute [instance] FullLattice.discrete FullLattice.full
namespace FullLattice
def hole {m : ℕ} (L : FullLattice m) (J : Set (Fin m → ℝ)) : ℝ≥0∞ :=
torusMeasure m ((latticeProjection L.module '' J)ᶜ)
end FullLattice
theorem common_horizontal_from_mean {m : ℕ} {X α : Type*} [MeasurableSpace X]
(μ : Measure X) [IsProbabilityMeasure μ] (family : X → FullLattice m)
(J : α → Set (Fin m → ℝ)) (s : Finset α) (Dh CR η τ N : ℝ)
(hCR : 0 ≤ CR) (hDh : 0 < Dh)
(hcov : ∀ x, ZLattice.covolume (family x).module=Dh)
(hmeas : ∀ a ∈ s, Measurable (fun x => (family x).hole (J a)))
(hmean : ∀ a ∈ s, ∫⁻ x, (family x).hole (J a) ∂μ ≤
ENNReal.ofReal (Real.exp (-(volume (J a)).toReal/Dh)+CR*Real.exp (-η)))
(hlo : ∀ a ∈ s, τ ≤ (volume (J a)).toReal/Dh)
(hhi : ∀ a ∈ s, (volume (J a)).toReal/Dh ≤ η)
(hcard : (s.card : ℝ) ≤ N)
(hcriterion : (1+CR)*N*Real.exp (-τ/2)<1) :
∃ L : FullLattice m, ZLattice.covolume L.module=Dh ∧
∀ a ∈ s, L.hole (J a) ≤ ENNReal.ofReal (Real.exp (-((volume (J a)).toReal/Dh)/2)) := by
have _ := hDh
have hsum : (1+CR)*(∑ a ∈ s, Real.exp (-((volume (J a)).toReal/Dh)/2))<1 := by
apply lt_of_le_of_lt _ hcriterion
calc
_ ≤ (1+CR)*(∑ a ∈ s, Real.exp (-τ/2)) := mul_le_mul_of_nonneg_left
(Finset.sum_le_sum (fun a ha => Real.exp_le_exp.mpr (by linarith [hlo a ha]))) (by linarith)
_ = (1+CR)*(s.card : ℝ)*Real.exp (-τ/2) := by rw [Finset.sum_const, nsmul_eq_mul]; ring
_ ≤ _ := mul_le_mul_of_nonneg_right (mul_le_mul_of_nonneg_left hcard (by linarith)) (Real.exp_pos _).le
obtain ⟨x,hx⟩ := common_hole_sample μ s (fun a x => (family x).hole (J a))
(fun a => (volume (J a)).toReal/Dh) CR η hCR hmeas hhi (by
intro a ha
simpa only [neg_div] using hmean a ha) hsum
exact ⟨family x,hcov x,hx⟩
end SingleLatticeCovering.Horizontal
end
end
section
noncomputable section
namespace SingleLatticeCovering.Assembly
open MeasureTheory Folded LatticeGeometry Completion Shear CoverGeometry Vertical Sections Horizontal
open scoped BigOperators Pointwise ENNReal
theorem sections_and_mean_cover {B : Block} (c : Chain B) {m : ℕ}
(hm : 2 ≤ m) (hD : 0 < c.fullDim)
(K : Set (Fin (m+c.fullDim) → ℝ)) (hK : IsCompact K) (hconv : Convex ℝ K)
(hV : 0 < (volume K).toReal) {R : ℝ} (hR : 0 < R)
(hrad : c.radiusSq+(B.terminalDim : ℝ) ≤ R^2)
(hsmall : R^2/(m : ℝ)^2 ≤ 1)
(hgauss : ∀ y : c.FullVec, ‖WithLp.toLp 2 y‖ ≤ 6*(c.fullDim : ℝ)*R →
(volume K).toReal*gamma y/2 ≤ (volume (coordinateFiber K y)).toReal)
(κ ρ ε τ A CR : ℝ) (hρ : 0 < ρ) (hτ : 0 ≤ τ) (hA : 0 < A) (hCR : 0 ≤ CR)
(hpat : ∀ y : c.FullVec, ∃ P : Finset c.FullVec,
P.Nonempty ∧ SuffixBinary P ∧
(∀ l ∈ P, l ∈ c.fullRaw ∧ c.FullResidual y l ∧ c.det*gamma (y-c.fullLinear l) ≤ ε) ∧
κ ≤ ∑ l ∈ P, c.det*gamma (y-c.fullLinear l))
(hload : A+(2^c.fullDim : ℕ)*τ ≤ (Real.exp (-1)/8)*κ*ρ)
(hcap : (Real.exp 1/8)*ρ*ε ≤ FinalRates.eta m)
(hcriterion : (1+CR)*(3*(m : ℝ)^2)^c.fullDim*Real.exp (-τ/2)<1)
(hcount : ∀ {α : Type} (s : Finset α), (s.card : ℝ) ≤ (3*(m : ℝ)^2)^c.fullDim →
let Lstar := 2*((patternTotal c.alphabetSeq s c.fullDim : ℝ)+1)
1 ≤ Lstar ∧ (patternTotal c.alphabetSeq s c.fullDim : ℝ)<Lstar ∧
Real.exp ((2 : ℝ)^c.fullDim*Real.log Lstar-A/2) ≤
1/((m+c.fullDim : ℕ) : ℝ)^(2*(m+c.fullDim)))
{X : Type*} [MeasurableSpace X] (μ : Measure X) [IsProbabilityMeasure μ]
(family : X → FullLattice m)
(hcov : ∀ x, ZLattice.covolume (family x).module volume=(volume K).toReal/(ρ*c.det))
(hmeas : ∀ J : Set (Fin m → ℝ), IsCompact J → Convex ℝ J → (interior J).Nonempty →
Measurable (fun x => (family x).hole J))
(hmean : ∀ J : Set (Fin m → ℝ), IsCompact J → Convex ℝ J → (interior J).Nonempty →
(volume J).toReal/((volume K).toReal/(ρ*c.det)) ≤ FinalRates.eta m →
∫⁻ x, (family x).hole J ∂μ ≤
ENNReal.ofReal (Real.exp (-(volume J).toReal/((volume K).toReal/(ρ*c.det)))+
CR*Real.exp (-FinalRates.eta m))) :
∃ (Λ : Submodule ℤ (Fin (m+c.fullDim) → ℝ)) (_ : DiscreteTopology Λ),
IsZLattice ℝ Λ ∧ K+(Λ : Set (Fin (m+c.fullDim) → ℝ))=Set.univ ∧
(volume K).toReal/ZLattice.covolume Λ volume ≤ Real.exp 1*ρ := by
classical
let Dh := (volume K).toReal/(ρ*c.det)
have hDh : 0 < Dh := div_pos hV (mul_pos hρ c.det_pos)
obtain ⟨e,heK,heconv,hevol,S,hSc,J,hJ,hsections⟩ :=
coordinate_marginal_to_labels hm hD hK hconv hV hR hsmall hgauss
let α := {a // a ∈ S}
let J' : α → Set (Fin m → ℝ) := fun a => J a.val
let u : α → ℝ := fun a => (volume (J' a)).toReal/Dh
let s : Finset α := Finset.univ.filter (fun a => τ ≤ u a ∧ u a ≤ (Real.exp 1/8)*ρ*ε)
have hcard : (s.card : ℝ) ≤ (3*(m : ℝ)^2)^c.fullDim := by
have hh : s.card ≤ S.card := by
calc
s.card ≤ (Finset.univ : Finset α).card := Finset.card_le_card (Finset.filter_subset _ _)
_ = S.card := by simp [α]
exact (by exact_mod_cast hh : (s.card : ℝ) ≤ S.card).trans hSc
have hulo (a : α) (ha : a ∈ s) : τ ≤ u a := (Finset.mem_filter.mp ha).2.1
have huhi (a : α) (ha : a ∈ s) : u a ≤ FinalRates.eta m :=
((Finset.mem_filter.mp ha).2.2).trans hcap
obtain ⟨L,hLc,hLhole⟩ := common_horizontal_from_mean μ family J' s Dh CR
(FinalRates.eta m) τ ((3*(m : ℝ)^2)^c.fullDim) hCR hDh hcov (by
intro a ha
exact hmeas (J' a) (hJ a.val a.property).1 (hJ a.val a.property).2.1 (hJ a.val a.property).2.2)
(by
intro a ha
exact hmean (J' a) (hJ a.val a.property).1 (hJ a.val a.property).2.1
(hJ a.val a.property).2.2 (huhi a ha)) hulo huhi hcard hcriterion
let Lstar := 2*((patternTotal c.alphabetSeq s c.fullDim : ℝ)+1)
obtain ⟨hLstar,hcost,herror⟩ := hcount s hcard
have hV' : 0 < (volume (e '' K)).toReal := by rwa [hevol]
have hcov' : ZLattice.covolume L.module volume=(volume (e '' K)).toReal/(ρ*c.det) := by
rw [hevol]; exact hLc
obtain ⟨Λ,hd,hfull,hcover,hbound⟩ := labeled_chain_to_cover c (by omega) L.module (e '' K)
heK heconv hV' J' (fun a => (hJ a.val a.property).1)
κ ρ (Real.exp (-1)/8) (Real.exp 1/8) ε τ A Lstar hρ (by positivity) (by positivity)
hτ hA hcov' hpat (by
intro v hv
obtain ⟨a,ha,hin,hl,hu⟩ := hsections v (hv.trans hrad)
exact ⟨⟨a,ha⟩,hin,hl,hu⟩) (by
intro a hlo hhi
have ha : a ∈ s := by
apply Finset.mem_filter.mpr
refine ⟨Finset.mem_univ _,?_,?_⟩
· simpa only [hLc] using hlo
· simpa only [hLc] using hhi
simpa only [FullLattice.hole,hLc] using hLhole a ha) hload hLstar (by
simpa only [hLc,s,u,patternTotal,Lstar] using hcost) (by
simpa only [Nat.cast_pow,Nat.cast_ofNat] using herror)
let := hd
let := hfull
exact pull_back_cover e K Λ hcover hbound
end SingleLatticeCovering.Assembly
end
end
section
noncomputable section
namespace SingleLatticeCovering.Inputs
open MeasureTheory Completion Horizontal Sections
open scoped ENNReal
structure MeanHoleModel (m : ℕ) (Dh CR : ℝ) where
Sample : Type
measurable : MeasurableSpace Sample
measure : @Measure Sample measurable
probability : @IsProbabilityMeasure Sample measurable measure
lattice : Sample → FullLattice m
covolume : ∀ x, ZLattice.covolume (lattice x).module volume=Dh
measurable_hole : letI := measurable
∀ J : Set (Fin m → ℝ), IsCompact J → Convex ℝ J → (interior J).Nonempty →
Measurable (fun x => (lattice x).hole J)
mean : letI := measurable
∀ J : Set (Fin m → ℝ), IsCompact J → Convex ℝ J → (interior J).Nonempty →
(volume J).toReal/Dh ≤ FinalRates.eta m →
∫⁻ x, (lattice x).hole J ∂measure ≤
ENNReal.ofReal (Real.exp (-(volume J).toReal/Dh)+CR*Real.exp (-FinalRates.eta m))
def GaussianPositions (α β γ C₀ : ℝ) (n : ℕ) : Prop :=
∀ m D : ℕ, m+D=n → 0 < D → (D : ℝ) ≤ (n : ℝ)^α →
∀ K : Set (Fin (m+D) → ℝ), IsCompact K → Convex ℝ K → (interior K).Nonempty →
∃ e : (Fin (m+D) → ℝ) ≃ᵃ[ℝ] (Fin (m+D) → ℝ),
∀ y : Fin D → ℝ, ‖WithLp.toLp 2 y‖ ≤ (n : ℝ)^β →
(1-C₀*(n : ℝ)^(-γ))*(volume (e '' K)).toReal*Folded.gamma y ≤
(volume (coordinateFiber (e '' K) y)).toReal
end SingleLatticeCovering.Inputs
end
end
section
noncomputable section
namespace SingleLatticeCovering.FinalRates
open Real Filter Topology
def sectionRadius (C : ℝ) (n : ℕ) : ℝ := (C+1)*((firstSize n : ℝ)+1)
lemma sectionRadius_pos {C : ℝ} (hC : 0 < C) (n : ℕ) : 0 < sectionRadius C n := by
dsimp [sectionRadius]; positivity
lemma radius_sq_bound {C b r : ℝ} (hC : 0 ≤ C) (hb : 0 ≤ b)
(hr : r ≤ C*(b*Real.log (b+1)+1)) : r ≤ ((C+1)*(b+1))^2 := by
have hl : Real.log (b+1) ≤ b := by simpa using Real.log_le_sub_one_of_pos (by linarith : 0 < b+1)
have hinner : b*Real.log (b+1)+1 ≤ (b+1)^2 := by nlinarith [mul_le_mul_of_nonneg_left hl hb]
calc
r ≤ C*(b*Real.log (b+1)+1) := hr
_ ≤ C*(b+1)^2 := mul_le_mul_of_nonneg_left hinner hC
_ ≤ (C+1)^2*(b+1)^2 := mul_le_mul_of_nonneg_right (by nlinarith [sq_nonneg C]) (sq_nonneg _)
_ = _ := by ring
lemma eventually_first_polynomial {H r ε : ℝ} (hH : 0 < H) (hr : 0 < r) (hε : 0 < ε) (k : ℕ) :
∀ᶠ n : ℕ in atTop, H*((firstSize n : ℝ)+1)^k ≤ ε*(n : ℝ)^r := by
filter_upwards [eventually_firstSize_le_log (by norm_num : (0 : ℝ) < 1),
eventually_log_power_bound k hr (div_pos hε hH)] with n hfirst hlog
simp only [one_mul] at hfirst
calc
_ ≤ H*(Real.log (n : ℝ))^k := mul_le_mul_of_nonneg_left
(pow_le_pow_left₀ (by positivity) hfirst k) hH.le
_ ≤ H*((ε/H)*(n : ℝ)^r) := mul_le_mul_of_nonneg_left hlog hH.le
_ = _ := by field_simp
lemma eventually_marginal_scales {C α β γ C₀ : ℝ} (hC : 0 < C)
(hα : 0 < α) (hβ : 0 < β) (hγ : 0 < γ) (hC₀ : 0 ≤ C₀) :
∀ᶠ n : ℕ in atTop, ∀ D : ℕ, (D : ℝ) ≤ C*((firstSize n : ℝ)+1) →
D ≤ n ∧ 2 ≤ n-D ∧ (D : ℝ) ≤ (n : ℝ)^α ∧
6*(D : ℝ)*sectionRadius C n < (n : ℝ)^β ∧
C₀*(n : ℝ)^(-γ) ≤ 1/2 ∧
sectionRadius C n^2/((n-D : ℕ) : ℝ)^2 ≤ 1 := by
have _ := hC₀
have herr : ∀ᶠ n : ℕ in atTop, C₀*(n : ℝ)^(-γ) ≤ 1/2 := by
have ht : Tendsto (fun n : ℕ => C₀*(n : ℝ)^(-γ)) atTop (𝓝 0) := by
have hn : Tendsto (fun n : ℕ => (n : ℝ)) atTop atTop := tendsto_natCast_atTop_atTop
simpa only [mul_zero,Function.comp_def] using ((tendsto_rpow_neg_atTop hγ).comp hn).const_mul C₀
exact ht.eventually (eventually_le_nhds (by norm_num : (0 : ℝ) < 1/2))
filter_upwards [eventually_first_polynomial hC hα (by norm_num : (0 : ℝ) < 1) 1,
eventually_first_polynomial (show 0 < 6*C*(C+1) by positivity) hβ (by norm_num : (0 : ℝ) < 1/2) 2,
eventually_first_polynomial (show 0 < C+1 by linarith) (by norm_num : (0 : ℝ) < 1)
(by norm_num : (0 : ℝ) < 1/2) 1,
eventually_dimension_small hC,herr,eventually_ge_atTop (4 : ℕ)] with n hDim hRad hSmall hDsmall he hn D hD
simp only [pow_one,one_mul] at hDim
simp only [pow_one,Real.rpow_one] at hSmall
have hn4 : (4 : ℝ) ≤ n := by exact_mod_cast hn
have hn0 : (0 : ℝ) < n := by linarith
have hdhalf := (hDsmall D hD).2
have hDn : D ≤ n := by exact_mod_cast (show (D : ℝ) ≤ n by linarith)
have hmhalf : (n : ℝ)/2 ≤ ((n-D : ℕ) : ℝ) := by rw [Nat.cast_sub hDn]; linarith
have hm2 : (2 : ℝ) ≤ ((n-D : ℕ) : ℝ) := by linarith
refine ⟨hDn,by exact_mod_cast hm2,hD.trans hDim,?_,he,?_⟩
· have hDR : 6*(D : ℝ)*sectionRadius C n ≤ 6*C*(C+1)*((firstSize n : ℝ)+1)^2 := by
dsimp [sectionRadius]
have hh := mul_le_mul_of_nonneg_right hD (show 0 ≤ 6*((C+1)*((firstSize n : ℝ)+1)) by positivity)
nlinarith
have hp : 0 < (n : ℝ)^β := Real.rpow_pos_of_pos hn0 β
exact hDR.trans_lt (hRad.trans_lt (by nlinarith))
· have hRm : sectionRadius C n ≤ ((n-D : ℕ) : ℝ) := by
dsimp [sectionRadius]
linarith
apply (div_le_one (sq_pos_of_pos (by linarith : (0 : ℝ) < ((n-D : ℕ) : ℝ)))).mpr
exact pow_le_pow_left₀ (sectionRadius_pos hC n).le hRm 2
end SingleLatticeCovering.FinalRates
end
end
section
noncomputable section
namespace SingleLatticeCovering.Assembly
open MeasureTheory Folded LatticeGeometry Completion Shear CoverGeometry Vertical Sections Horizontal Inputs
open Filter Topology
open scoped BigOperators Pointwise ENNReal
lemma body_volume_pos {n : ℕ} {K : Set (Fin n → ℝ)} (hK : IsCompact K)
(hi : (interior K).Nonempty) : 0 < (volume K).toReal := by
apply ENNReal.toReal_pos (ne_of_gt ?_) hK.measure_ne_top
exact (isOpen_interior.measure_pos volume hi).trans_le (measure_mono interior_subset)
lemma affine_body {n : ℕ} (e : (Fin n → ℝ) ≃ᵃ[ℝ] (Fin n → ℝ))
{K : Set (Fin n → ℝ)} (hK : IsCompact K) (hc : Convex ℝ K) (hi : (interior K).Nonempty) :
IsCompact (e '' K) ∧ Convex ℝ (e '' K) ∧ (interior (e '' K)).Nonempty := by
let he : (Fin n → ℝ) ≃ₜ (Fin n → ℝ) :=
{ toEquiv := e.toEquiv
continuous_toFun := e.toAffineMap.continuous_of_finiteDimensional
continuous_invFun := e.symm.toAffineMap.continuous_of_finiteDimensional }
refine ⟨hK.image he.continuous, hc.affine_image e.toAffineMap,?_⟩
change (interior (he '' K)).Nonempty
rw [←he.image_interior]
exact hi.image he
lemma chain_first_le_dim {B : Block} (c : Chain B) : c.first.b ≤ c.dim := by
induction c with
| base B => rfl
| append c B w ih => exact ih.trans (Nat.le_add_right _ _)
def coversAtBound (n : ℕ) (d : ℝ) : Prop :=
∀ K : Set (Fin n → ℝ), IsCompact K → Convex ℝ K → (interior K).Nonempty →
∃ (Λ : Submodule ℤ (Fin n → ℝ)) (_ : DiscreteTopology Λ), IsZLattice ℝ Λ ∧
K+(Λ : Set (Fin n → ℝ))=Set.univ ∧
(volume K).toReal/ZLattice.covolume Λ volume ≤ d
theorem eventual_main_reduction {α β γ C₀ CR : ℝ}
(hα : 0 < α) (hβ : 0 < β) (hγ : 0 < γ) (hC₀ : 0 ≤ C₀) (hCR : 0 ≤ CR)
(hGaussian : ∀ᶠ n : ℕ in atTop, GaussianPositions α β γ C₀ n)
(hMean : ∀ m : ℕ, 2 ≤ m → ∀ Dh : ℝ, 0 < Dh → Nonempty (MeanHoleModel m Dh CR)) :
∃ C : ℝ, 0 < C ∧ ∀ᶠ n : ℕ in atTop, ∀ K : Set (Fin n → ℝ),
IsCompact K → Convex ℝ K → (interior K).Nonempty →
∃ (Λ : Submodule ℤ (Fin n → ℝ)) (_ : DiscreteTopology Λ), IsZLattice ℝ Λ ∧
K+(Λ : Set (Fin n → ℝ))=Set.univ ∧
(volume K).toReal/ZLattice.covolume Λ volume ≤ C*(n : ℝ)*Real.log (n : ℝ) := by
classical
obtain ⟨cutoff,hcut,C,k,κ,hC,hk,hκ,hvertical⟩ := vertical_patterns_alphabets
obtain ⟨Cstar,hstar,hconditions⟩ := FinalRates.final_conditions hC hk
(show 0 < Real.exp (-1)/8 by positivity) (show 0 ≤ Real.exp 1/8 by positivity)
hκ (show (1 : ℝ) ≤ 3 by norm_num) hCR
refine ⟨Real.exp 1*Cstar,by positivity,?_⟩
filter_upwards [hconditions,FinalRates.eventually_marginal_scales hC hα hβ hγ hC₀,
FinalRates.firstSize_tendsto.eventually (eventually_ge_atTop cutoff), hGaussian]
with n hn hscale hfirst hgaussian
obtain ⟨B,c,hcb,hcs,hDim,hRad,hAlphabet,hPattern⟩ := hvertical (FinalRates.firstSize n) hfirst
have hDdim : (c.fullDim : ℝ) ≤ C*((FinalRates.firstSize n : ℝ)+1) := by
simpa [Chain.fullDim,Nat.cast_add] using hDim
obtain ⟨hDn,hm,hcap,hload,hcrit,hcount⟩ := hn.2 c.fullDim hDdim
obtain ⟨_,_,hDpower,hRadius,hErr,hSmall⟩ := hscale c.fullDim hDdim
have hD : 0 < c.fullDim := by
have hfirstdim := chain_first_le_dim c
rw [hcb] at hfirstdim
dsimp [Chain.fullDim]
omega
let m := n-c.fullDim
have hmn : m+c.fullDim=n := Nat.sub_add_cancel hDn
have hmnle : m ≤ n := Nat.sub_le _ _
have hnpos : (0 : ℝ) < n := by exact_mod_cast (show 0 < n by omega)
have hnlog : 0 < Real.log (n : ℝ) := Real.log_pos (by exact_mod_cast (show 1 < n by omega))
let ρ := Cstar*(n : ℝ)*Real.log (n : ℝ)
let ε := Real.exp (-k*(FinalRates.firstSize n : ℝ)^(70/100 : ℝ))
let R := FinalRates.sectionRadius C n
have hρ : 0 < ρ := by dsimp [ρ]; positivity
have hrad : c.radiusSq+(B.terminalDim : ℝ) ≤ R^2 :=
FinalRates.radius_sq_bound hC.le (Nat.cast_nonneg _) hRad
have step : coversAtBound (m+c.fullDim) ((Real.exp 1*Cstar)*(n : ℝ)*Real.log (n : ℝ)) := by
intro K hK hc hi
obtain ⟨e,he⟩ := hgaussian m c.fullDim hmn hD hDpower K hK hc hi
obtain ⟨heK,hec,hei⟩ := affine_body e hK hc hi
have heV := body_volume_pos heK hei
have hg : ∀ y : c.FullVec, ‖WithLp.toLp 2 y‖ ≤ 6*(c.fullDim : ℝ)*R →
(volume (e '' K)).toReal*gamma y/2 ≤ (volume (coordinateFiber (e '' K) y)).toReal := by
intro y hy
apply le_trans _ (he y (hy.trans hRadius.le))
have hy0 : 0 < gamma y := Finset.prod_pos (fun j _ => gamma1_pos _)
nlinarith [mul_nonneg (show 0 ≤ 1-C₀*(n : ℝ)^(-γ)-1/2 by linarith)
(mul_nonneg heV.le hy0.le)]
obtain ⟨model⟩ := hMean m hm ((volume (e '' K)).toReal/(ρ*c.det))
(div_pos heV (mul_pos hρ c.det_pos))
let := model.measurable
let := model.probability
obtain ⟨Λ,hd,hfull,hcover,hbound⟩ := sections_and_mean_cover c hm hD (e '' K) heK hec heV
(FinalRates.sectionRadius_pos hC n) hrad hSmall hg κ ρ ε (Real.sqrt (m : ℝ))
(8*(n : ℝ)*Real.log (n : ℝ)) CR hρ (Real.sqrt_nonneg _) (by positivity) hCR
(by
intro y
obtain ⟨P,hPn,hPb,hPl,hPt,hPw⟩ := hPattern y
exact ⟨P,hPn,hPb,hPl,hPw⟩)
(by simpa only [Nat.cast_pow,Nat.cast_ofNat] using hload) hcap hcrit (by
intro δ s hs
have hs' : (s.card : ℝ) ≤ (3*(n : ℝ)^2)^c.fullDim := hs.trans (by
gcongr)
have ha : ∀ j < c.fullDim, Real.log ((c.alphabetSeq j).card+1 : ℝ) ≤
Real.log 8+(c.fullDim : ℝ)*Real.log ((c.fullDim : ℝ)+2)+(FinalRates.firstSize n : ℝ)^2 := by
intro j hj
simpa only [c.alphabetSeq_fin ⟨j,hj⟩] using hAlphabet ⟨j,hj⟩
simpa only [Nat.sub_add_cancel hDn] using hcount s c.alphabetSeq hs' ha)
model.measure model.lattice model.covolume model.measurable_hole model.mean
let := hd
let := hfull
have hb : (volume (e '' K)).toReal/ZLattice.covolume Λ volume ≤
(Real.exp 1*Cstar)*(n : ℝ)*Real.log (n : ℝ) := by
convert hbound using 1 ; dsimp [ρ] ; ring
exact pull_back_cover e K Λ hcover hb
change coversAtBound n ((Real.exp 1*Cstar)*(n : ℝ)*Real.log (n : ℝ))
simpa only [hmn] using step
end SingleLatticeCovering.Assembly
end
end
section
noncomputable section
open Set Module MeasureTheory
open scoped BigOperators Pointwise
namespace SingleLatticeCovering.FiniteDimensions
theorem maximal_basis {n : ℕ} (K : Set (Fin n → ℝ)) (hK : IsCompact K)
(h0 : (0 : Fin n → ℝ) ∈ interior K) :
∃ b : Basis (Fin n) ℝ (Fin n → ℝ),
(∀ j, b j ∈ K) ∧ ∀ x ∈ K, ∀ j, |b.repr x j| ≤ 1 := by
classical
obtain ⟨r,hr,hball⟩ := Metric.mem_nhds_iff.mp (mem_interior_iff_mem_nhds.mp h0)
let v₀ : Fin n → (Fin n → ℝ) := fun j => (r/2) • Pi.single j (1 : ℝ)
have hv₀ : ∀ j, v₀ j ∈ K := by
intro j
apply hball
rw [Metric.mem_ball,dist_zero_right]
simp only [v₀,norm_smul,Pi.norm_single,Real.norm_eq_abs,abs_one,mul_one,
abs_of_pos (by positivity : 0 < r/2)]
linarith
have hdet₀ : (Matrix.of v₀).det = (r/2)^n := by
have he : Matrix.of v₀ = (r/2) • (1 : Matrix (Fin n) (Fin n) ℝ) := by
ext i j
simp [v₀,Pi.single_apply,Matrix.one_apply,Pi.smul_apply,eq_comm]
rw [he,Matrix.det_smul,Matrix.det_one,mul_one,Fintype.card_fin]
have hS : IsCompact {v : Fin n → (Fin n → ℝ) | ∀ j, v j ∈ K} :=
isCompact_pi_infinite (fun _ => hK)
have hcont : Continuous (fun v : Fin n → (Fin n → ℝ) => |(Matrix.of v).det|) := by
fun_prop
obtain ⟨v,hv,hmax⟩ := hS.exists_isMaxOn ⟨v₀,hv₀⟩ hcont.continuousOn
have hdet : (Matrix.of v).det ≠ 0 := by
have h : |(Matrix.of v₀).det| ≤ |(Matrix.of v).det| := hmax hv₀
rw [hdet₀,abs_of_pos (pow_pos (by positivity : 0 < r/2) _)] at h
intro hz
rw [hz,abs_zero] at h
exact (not_le_of_gt (pow_pos (by positivity : 0 < r/2) _)) h
let b := basisOfLinearIndependentOfCardEqFinrank' v
(Matrix.linearIndependent_rows_of_det_ne_zero hdet) (by simp)
have hb : (b : Fin n → (Fin n → ℝ)) = v := by
simp [b]
refine ⟨b,?_,?_⟩
· intro j
rw [show b j=v j from congrFun hb j]
exact hv j
· intro x hx j
have hupdate : (Function.update v j x) ∈ {v : Fin n → (Fin n → ℝ) | ∀ j, v j ∈ K} := by
intro k
by_cases hk : k=j
· subst k; simpa using hx
· simpa [hk] using hv k
have hbound := hmax hupdate
have hd : (Matrix.of (Function.update v j x)).det = b.repr x j*(Matrix.of v).det := by
have hs := b.sum_repr x
have ht := Matrix.det_updateRow_sum (Matrix.of b) j (fun k => b.repr x k)
change (Matrix.of (Function.update (fun k => b k) j (∑ k, b.repr x k • b k))).det =
b.repr x j*(Matrix.of b).det at ht
rw [hs,hb] at ht
exact ht
change |(Matrix.of (Function.update v j x)).det| ≤ |(Matrix.of v).det| at hbound
rw [hd,abs_mul] at hbound
exact (mul_le_mul_iff_left₀ (abs_pos.mpr hdet)).mp (by simpa [mul_comm] using hbound)
end SingleLatticeCovering.FiniteDimensions
namespace SingleLatticeCovering.FiniteDimensions
open MeasureTheory Module Set Completion Vertical LatticeGeometry
open scoped BigOperators Pointwise
lemma convex_basis_cube {n : ℕ} (hn : 0 < n) (K : Set (Fin n → ℝ))
(hconv : Convex ℝ K) (h0 : (0 : Fin n → ℝ) ∈ K)
(b : Basis (Fin n) ℝ (Fin n → ℝ)) (hb : ∀ j, b j ∈ K) :
Icc (0 : Fin n → ℝ) (fun _ => 1/(n : ℝ)) ⊆ b.equivFun.symm ⁻¹' K := by
intro x hx
have hnr : (0 : ℝ) < n := by exact_mod_cast hn
have hsum : ∑ j, x j ≤ 1 := calc
∑ j, x j ≤ ∑ _j : Fin n, 1/(n : ℝ) := Finset.sum_le_sum (fun j _ => hx.2 j)
_ = 1 := by simp [hnr.ne']
let w : Fin (n+1) → ℝ := Fin.cons (1-∑ j, x j) x
let z : Fin (n+1) → (Fin n → ℝ) := Fin.cons 0 b
have hw : ∀ j ∈ (Finset.univ : Finset (Fin (n+1))), 0 ≤ w j := by
intro j _
refine Fin.cases ?_ (fun i => ?_) j
· exact sub_nonneg.mpr hsum
· exact hx.1 i
have hw1 : ∑ j, w j = 1 := by simp [w,Fin.sum_univ_succ]
have hz : ∀ j ∈ (Finset.univ : Finset (Fin (n+1))), z j ∈ K := by
intro j _
exact Fin.cases h0 hb j
have hc := hconv.sum_mem hw hw1 hz
change b.equivFun.symm x ∈ K
rw [Basis.equivFun_symm_apply]
simpa only [Fin.sum_univ_succ,w,z,Fin.cons_zero,Fin.cons_succ,smul_zero,zero_add] using hc
lemma integer_cube_cover {n : ℕ} (hn : 0 < n) :
Icc (0 : Fin n → ℝ) (fun _ => 1/(n : ℝ))+
(contractLattice (integerLattice n) (n : ℝ) (by exact_mod_cast hn.ne') : Set (Fin n → ℝ)) =
Set.univ := by
apply Set.eq_univ_of_forall
intro x
have hnr : (0 : ℝ) < n := by exact_mod_cast hn
let l : Fin n → ℝ := fun j => (⌊(n : ℝ)*x j⌋ : ℤ)/(n : ℝ)
let q : Fin n → ℝ := fun j => Int.fract ((n : ℝ)*x j)/(n : ℝ)
have hl : l ∈ contractLattice (integerLattice n) (n : ℝ) (by exact_mod_cast hn.ne') := by
rw [mem_contractLattice]
convert integer_mem n (fun j => ⌊(n : ℝ)*x j⌋) using 1
ext j
simp only [Pi.smul_apply,smul_eq_mul,l]
field_simp
refine ⟨q,⟨?_,?_⟩,l,hl,?_⟩
· intro j
exact div_nonneg (Int.fract_nonneg _) hnr.le
· intro j
exact (div_le_div_iff_of_pos_right hnr).mpr (Int.fract_lt_one _).le
· ext j
change Int.fract ((n : ℝ)*x j)/(n : ℝ)+(⌊(n : ℝ)*x j⌋ : ℤ)/(n : ℝ)=x j
rw [←add_div,Int.fract_add_floor]
exact mul_div_cancel_left₀ _ hnr.ne'
end SingleLatticeCovering.FiniteDimensions
namespace SingleLatticeCovering.FiniteDimensions
open MeasureTheory Module Set Completion Vertical LatticeGeometry
open scoped BigOperators Pointwise
theorem finite_dimension_cover {n : ℕ} (hn : 0 < n)
(K : Set (Fin n → ℝ)) (hK : IsCompact K) (hconv : Convex ℝ K)
(hinterior : (interior K).Nonempty) :
∃ (L : Submodule ℤ (Fin n → ℝ)) (_ : DiscreteTopology L),
IsZLattice ℝ L ∧ K+(L : Set (Fin n → ℝ))=univ ∧
(volume K).toReal / ZLattice.covolume L ≤ (2*(n : ℝ))^n := by
classical
obtain ⟨x₀,hx₀⟩ := hinterior
let t := Homeomorph.addRight x₀
let K₀ := t ⁻¹' K
have hK₀ : IsCompact K₀ := t.isCompact_preimage.mpr hK
have h0 : (0 : Fin n → ℝ) ∈ interior K₀ := by
rw [←t.preimage_interior]
change 0+x₀ ∈ interior K
simpa using hx₀
have hconv₀ : Convex ℝ K₀ := by
intro x hx y hy a b ha hb hab
have hh := hconv hx hy ha hb hab
change a • (x+x₀)+b • (y+x₀) ∈ K at hh
change a • x+b • y+x₀ ∈ K
have he : a • (x+x₀)+b • (y+x₀) = a • x+b • y+x₀ := by
calc
_ = (a • x+b • y)+(a+b) • x₀ := by module
_ = _ := by rw [hab,one_smul]
rwa [he] at hh
obtain ⟨b,hb,hbound⟩ := maximal_basis K₀ hK₀ h0
let e := b.equivFun.symm
let K' := e ⁻¹' K₀
have hsmall : Icc (0 : Fin n → ℝ) (fun _ => 1/(n : ℝ)) ⊆ K' :=
convex_basis_cube hn K₀ hconv₀ (interior_subset h0) b hb
have hlarge : K' ⊆ Icc (fun _ : Fin n => (-1 : ℝ)) (fun _ => 1) := by
intro x hx
have hb' := hbound (e x) hx
have hj (j : Fin n) : |x j| ≤ 1 := by
have hh : |b.equivFun (e x) j| ≤ 1 := hb' j
simpa only [e,LinearEquiv.apply_symm_apply] using hh
exact ⟨fun j => (abs_le.mp (hj j)).1,fun j => (abs_le.mp (hj j)).2⟩
have hnr : (0 : ℝ) < n := by exact_mod_cast hn
let L₀ := contractLattice (integerLattice n) (n : ℝ) hnr.ne'
have hcover : K'+(L₀ : Set (Fin n → ℝ))=univ := by
apply Set.eq_univ_of_univ_subset
rw [←integer_cube_cover hn]
exact Set.add_subset_add_right hsmall
have hvolume : (volume K').toReal ≤ (2 : ℝ)^n := by
have hh := ENNReal.toReal_mono (isCompact_Icc.measure_ne_top (μ := volume)) (measure_mono hlarge)
rw [Real.volume_Icc_pi_toReal (by intro j; norm_num)] at hh
norm_num at hh
exact hh
have hcov : ZLattice.covolume L₀ = (n : ℝ)⁻¹^n := by
rw [contractLattice_covolume _ _ hnr,integerLattice_covolume,mul_one]
have hdens : (volume K').toReal / ZLattice.covolume L₀ ≤ (2*(n : ℝ))^n := by
rw [hcov,inv_pow,div_inv_eq_mul,mul_pow]
exact mul_le_mul_of_nonneg_right hvolume (pow_nonneg hnr.le _)
have himage : (fun x => e x+x₀) '' K'=K := by
ext x
constructor
· rintro ⟨y,hy,rfl⟩
exact hy
· intro hx
refine ⟨e.symm (x-x₀),?_,?_⟩
· change e (e.symm (x-x₀))+x₀ ∈ K
simpa using hx
· simp
refine ⟨image L₀ e,inferInstance,inferInstance,?_,?_⟩
· rw [←himage]
exact affine_image_cover L₀ e x₀ K' hcover
· rw [←himage,affine_image_density]
exact hdens
end SingleLatticeCovering.FiniteDimensions
end
end
end
end OAI