import Mathlib import OAI.Geometry.BallPacking.Normal.CubicToricAmbient namespace OAI noncomputable section namespace PackingSufficiencySupport.Hamiltonian open scoped ContDiff Manifold Topology open Set Function Manifold variable {E F : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E] [FiniteDimensional ℝ E] [NormedAddCommGroup F] [NormedSpace ℝ F] {M N : Type*} [TopologicalSpace M] [T2Space M] [NormalSpace M] [SigmaCompactSpace M] [ChartedSpace E M] [IsManifold 𝓘(ℝ,E) ∞ M] [TopologicalSpace N] [ChartedSpace F N] theorem exists_compact_exact_fibre_embedding {Γ : ℝ → ManifoldOneForm E M} (hΓ : SmoothOneFormFamily Γ) {K : Set M} (hK : IsCompact K) (hinv : ∀ x∈K,(manifoldExteriorOneForm (Γ 0) x).IsInvertible) {U : Set M} (hU : IsOpen U) (hKU : K⊆U) {δ : ℝ} (hδ : 0<δ) {A : ℝ × M → N} (hA : ContMDiff ((𝓘(ℝ,ℝ)).prod 𝓘(ℝ,E)) 𝓘(ℝ,F) ∞ A) (hemb : ∀ t∈Ioc (0:ℝ) δ,Topology.IsEmbedding (fun x : U => A (t,x.val))) (Ω : ℝ → ManifoldTwoForm F N) (hform : ∀ t∈Ioc (0:ℝ) δ,∀ x∈U, manifoldExteriorOneForm (Γ t) x=(Ω t (A (t,x))).bilinearComp (manifoldMapDifferential (E := F) (F := E) (fun y => A (t,y)) x) (manifoldMapDifferential (E := F) (F := E) (fun y => A (t,y)) x)) : ∃ t∈Ioc (0:ℝ) δ,∃ g : M → N,∃ W : Set M,IsOpen W ∧ K⊆W ∧ ContMDiff 𝓘(ℝ,E) 𝓘(ℝ,F) ∞ g ∧ Topology.IsEmbedding (fun x : W => g x.val) ∧ ∀ x∈W,∀ v w,Ω t (g x) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x w)=manifoldExteriorOneForm (Γ 0) x v w := by obtain ⟨ε,hε,_hε1,V,hV,hKV,Φ,Ψ,hΦ,hΨ,hΦ0,hΦinv,hΦform⟩ := exists_compact_short_exact_moser hΓ hK hinv have hS : IsOpen {p : ℝ × M | p.2∈V ∧ Φ p∈U} := (hV.preimage continuous_snd).inter (hU.preimage hΦ.continuous) have hKS : ({0}:Set ℝ)×ˢK⊆{p : ℝ × M | p.2∈V ∧ Φ p∈U} := by rintro ⟨t,x⟩ ⟨ht,hx⟩ rcases ht with rfl exact ⟨hKV hx,by simpa only [hΦ0] using hKU hx⟩ obtain ⟨T,W,hT,hW,h0T,hKW,hTW⟩ := generalized_tube_lemma isCompact_singleton hK hS hKS obtain ⟨η,hη,hηT⟩ := Metric.isOpen_iff.mp hT 0 (h0T (mem_singleton 0)) let t : ℝ := min (η/2) (min ε δ) have ht : 0 (t,x)) have hψ := hΨ.comp (contMDiff_const.prodMk contMDiff_id) (f := fun x : M => (t,x)) have hφemb : Topology.IsEmbedding (fun x : M => Φ (t,x)) := by apply Topology.IsEmbedding.of_comp hφ.continuous hψ.continuous have he : (fun x : M => Ψ (t,Φ (t,x)))=id := funext fun x => (hΦinv t ⟨ht.le,htε⟩ x).1 change Topology.IsEmbedding (fun x : M => Ψ (t,Φ (t,x))) rw [he] exact Topology.IsEmbedding.id have ha := hA.comp (contMDiff_const.prodMk contMDiff_id) (f := fun x : M => (t,x)) let g : M → N := (fun x => A (t,x)) ∘ (fun x => Φ (t,x)) refine ⟨t,⟨ht,htδ⟩,g,W,hW,hKW,ha.comp hφ,?_,?_⟩ · exact (hemb t ⟨ht,htδ⟩).comp ((hφemb.comp Topology.IsEmbedding.subtypeVal).codRestrict U (fun x : W => (hstay x.val x.property).2)) · intro x hx v w have hd := mfderiv_comp x (ha.mdifferentiable (by simp) (Φ (t,x))) (hφ.mdifferentiable (by simp) x) change Ω t (A (t,Φ (t,x))) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x w)=_ change Ω t (A (t,Φ (t,x))) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) ((A ∘ fun y => (t,y)) ∘ (Φ ∘ fun y => (t,y))) x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) ((A ∘ fun y => (t,y)) ∘ (Φ ∘ fun y => (t,y))) x w)=_ rw [hd] have hf := congrArg (fun B : E →L[ℝ] E →L[ℝ] ℝ => B (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,E) (fun y => Φ (t,y)) x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,E) (fun y => Φ (t,y)) x w)) (hform t ⟨ht,htδ⟩ (Φ (t,x)) (hstay x hx).2) exact hf.symm.trans (hΦform t ⟨ht.le,htε⟩ x (hstay x hx).1 v w) theorem exists_compact_exact_fibre_embedding_into {Γ : ℝ → ManifoldOneForm E M} (hΓ : SmoothOneFormFamily Γ) {K : Set M} (hK : IsCompact K) (hinv : ∀ x∈K,(manifoldExteriorOneForm (Γ 0) x).IsInvertible) {U : Set M} (hU : IsOpen U) (hKU : K⊆U) {δ : ℝ} (hδ : 0<δ) {A : ℝ × M → N} (hA : ContMDiff ((𝓘(ℝ,ℝ)).prod 𝓘(ℝ,E)) 𝓘(ℝ,F) ∞ A) (hemb : ∀ t∈Ioc (0:ℝ) δ,Topology.IsEmbedding (fun x : U => A (t,x.val))) {T : Set N} (hinto : ∀ t∈Ioc (0:ℝ) δ,MapsTo (fun x => A (t,x)) U T) (Ω : ℝ → ManifoldTwoForm F N) (hform : ∀ t∈Ioc (0:ℝ) δ,∀ x∈U, manifoldExteriorOneForm (Γ t) x=(Ω t (A (t,x))).bilinearComp (manifoldMapDifferential (E := F) (F := E) (fun y => A (t,y)) x) (manifoldMapDifferential (E := F) (F := E) (fun y => A (t,y)) x)) : ∃ t∈Ioc (0:ℝ) δ,∃ g : M → N,∃ W : Set M,IsOpen W ∧ K⊆W ∧ ContMDiff 𝓘(ℝ,E) 𝓘(ℝ,F) ∞ g ∧ Topology.IsEmbedding (fun x : W => g x.val) ∧ MapsTo g W T ∧ ∀ x∈W,∀ v w,Ω t (g x) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x w)=manifoldExteriorOneForm (Γ 0) x v w := by obtain ⟨ε,hε,_hε1,V,hV,hKV,Φ,Ψ,hΦ,hΨ,hΦ0,hΦinv,hΦform⟩ := exists_compact_short_exact_moser hΓ hK hinv have hS : IsOpen {p : ℝ × M | p.2∈V ∧ Φ p∈U} := (hV.preimage continuous_snd).inter (hU.preimage hΦ.continuous) have hKS : ({0}:Set ℝ)×ˢK⊆{p : ℝ × M | p.2∈V ∧ Φ p∈U} := by rintro ⟨t,x⟩ ⟨ht,hx⟩ rcases ht with rfl exact ⟨hKV hx,by simpa only [hΦ0] using hKU hx⟩ obtain ⟨T,W,hT,hW,h0T,hKW,hTW⟩ := generalized_tube_lemma isCompact_singleton hK hS hKS obtain ⟨η,hη,hηT⟩ := Metric.isOpen_iff.mp hT 0 (h0T (mem_singleton 0)) let t : ℝ := min (η/2) (min ε δ) have ht : 0 (t,x)) have hψ := hΨ.comp (contMDiff_const.prodMk contMDiff_id) (f := fun x : M => (t,x)) have hφemb : Topology.IsEmbedding (fun x : M => Φ (t,x)) := by apply Topology.IsEmbedding.of_comp hφ.continuous hψ.continuous have he : (fun x : M => Ψ (t,Φ (t,x)))=id := funext fun x => (hΦinv t ⟨ht.le,htε⟩ x).1 change Topology.IsEmbedding (fun x : M => Ψ (t,Φ (t,x))) rw [he] exact Topology.IsEmbedding.id have ha := hA.comp (contMDiff_const.prodMk contMDiff_id) (f := fun x : M => (t,x)) let g : M → N := (fun x => A (t,x)) ∘ (fun x => Φ (t,x)) refine ⟨t,⟨ht,htδ⟩,g,W,hW,hKW,ha.comp hφ,?_,?_,?_⟩ · exact (hemb t ⟨ht,htδ⟩).comp ((hφemb.comp Topology.IsEmbedding.subtypeVal).codRestrict U (fun x : W => (hstay x.val x.property).2)) · intro x hx exact hinto t ⟨ht,htδ⟩ (hstay x hx).2 · intro x hx v w have hd := mfderiv_comp x (ha.mdifferentiable (by simp) (Φ (t,x))) (hφ.mdifferentiable (by simp) x) change Ω t (A (t,Φ (t,x))) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x w)=_ change Ω t (A (t,Φ (t,x))) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) ((A ∘ fun y => (t,y)) ∘ (Φ ∘ fun y => (t,y))) x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) ((A ∘ fun y => (t,y)) ∘ (Φ ∘ fun y => (t,y))) x w)=_ rw [hd] have hf := congrArg (fun B : E →L[ℝ] E →L[ℝ] ℝ => B (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,E) (fun y => Φ (t,y)) x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,E) (fun y => Φ (t,y)) x w)) (hform t ⟨ht,htδ⟩ (Φ (t,x)) (hstay x hx).2) exact hf.symm.trans (hΦform t ⟨ht.le,htε⟩ x (hstay x hx).1 v w) theorem exists_compact_exact_fibre_embedding_central_into {Γ : ℝ → ManifoldOneForm E M} (hΓ : SmoothOneFormFamily Γ) {K : Set M} (hK : IsCompact K) (hinv : ∀ x∈K,(manifoldExteriorOneForm (Γ 0) x).IsInvertible) {U : Set M} (hU : IsOpen U) (hKU : K⊆U) {δ : ℝ} (hδ : 0<δ) {A : ℝ × M → N} (hA : ContMDiff ((𝓘(ℝ,ℝ)).prod 𝓘(ℝ,E)) 𝓘(ℝ,F) ∞ A) (hemb : ∀ t∈Ioc (0:ℝ) δ,Topology.IsEmbedding (fun x : U => A (t,x.val))) {T : Set N} (hT : IsOpen T) (hinto : MapsTo (fun x => A (0,x)) K T) (Ω : ℝ → ManifoldTwoForm F N) (hform : ∀ t∈Ioc (0:ℝ) δ,∀ x∈U, manifoldExteriorOneForm (Γ t) x=(Ω t (A (t,x))).bilinearComp (manifoldMapDifferential (E := F) (F := E) (fun y => A (t,y)) x) (manifoldMapDifferential (E := F) (F := E) (fun y => A (t,y)) x)) : ∃ t∈Ioc (0:ℝ) δ,∃ g : M → N,∃ W : Set M,IsOpen W ∧ K⊆W ∧ ContMDiff 𝓘(ℝ,E) 𝓘(ℝ,F) ∞ g ∧ Topology.IsEmbedding (fun x : W => g x.val) ∧ MapsTo g W T ∧ ∀ x∈W,∀ v w,Ω t (g x) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x v) (mfderiv 𝓘(ℝ,E) 𝓘(ℝ,F) g x w)=manifoldExteriorOneForm (Γ 0) x v w := by have hS : IsOpen (A ⁻¹' T) := hT.preimage hA.continuous have hKS : ({0}:Set ℝ)×ˢK⊆A ⁻¹' T := by rintro ⟨t,x⟩ ⟨ht,hx⟩ rcases ht with rfl exact hinto hx obtain ⟨V,W,hV,hW,h0V,hKW,hVW⟩ := generalized_tube_lemma isCompact_singleton hK hS hKS obtain ⟨η,hη,hηV⟩ := Metric.isOpen_iff.mp hV 0 (h0V (mem_singleton 0)) let δ' := min δ (η/2) have hδ' : 0<δ' := lt_min hδ (by positivity) have htδ {t : ℝ} (ht : t∈Ioc (0:ℝ) δ') : t∈Ioc (0:ℝ) δ := ⟨ht.1,ht.2.trans (min_le_left _ _)⟩ have htV {t : ℝ} (ht : t∈Ioc (0:ℝ) δ') : t∈V := by apply hηV rw [Metric.mem_ball,Real.dist_eq,sub_zero,abs_of_pos ht.1] have h := ht.2.trans (min_le_right δ (η/2)) linarith obtain ⟨t,ht,g,O,hO,hKO,hg,hge,hgT,hgf⟩ := exists_compact_exact_fibre_embedding_into hΓ hK hinv (hU.inter hW) (fun x hx => ⟨hKU hx,hKW hx⟩) hδ' hA (fun t ht => (hemb t (htδ ht)).comp (Topology.IsEmbedding.inclusion inter_subset_left)) (fun t ht x hx => hVW ⟨htV ht,hx.2⟩) Ω (fun t ht x hx => hform t (htδ ht) x hx.1) exact ⟨t,htδ ht,g,O,hO,hKO,hg,hge,hgT,hgf⟩ end PackingSufficiencySupport.Hamiltonian namespace PackingSufficiencySupport.CubicModel open scoped ContDiff Manifold Topology open Set Function Filter Manifold open DiagonalQuadrics DiagonalQuadrics.Explicit Hamiltonian FiniteMoment FiniteMoment.Radial abbrev CubicPhysicalModel := RealModel × PlanePhase (Fin 2) abbrev CubicPhysicalSpace := BaseCurve × PlanePhase (Fin 2) def cubicPhysicalForm {A B : ℕ} (D S : ℕ) (L : ℝ) : ManifoldTwoForm CubicPhysicalModel CubicPhysicalSpace := globalHorizontalCoupling phaseArea (physicalPrimitive (A := A) (B := B) D S (1/(L*Real.pi)) L ∘ planeMoments) theorem exists_actual_cubic_normal_transfer_into {A B : ℕ} (hA : 0 g x.val) ∧ MapsTo g W T ∧ ∀ x∈W,∀ v w,cubicAmbientForm (A := A) (B := B) D S (1/(L*Real.pi)) t (g x) (manifoldMapDifferential (E := CubicAmbient) (F := CubicPhysicalModel) g x v) (manifoldMapDifferential (E := CubicAmbient) (F := CubicPhysicalModel) g x w)= cubicPhysicalForm (A := A) (B := B) D S L x v w := by let : SigmaCompactSpace BaseCurve := curveSigmaCompact (parameters 0) have ha : ContMDiff 𝓘(ℝ,RealModel) 𝓘(ℝ,TrapezoidWeight A B → ℝ) ∞ (fun x : BaseCurve => coefficientSquares (cubicCoefficients D S x)) := coefficientSquares_contDiff.contMDiff.comp (cubicCoefficients_smooth D S) have hapos (x : BaseCurve) (i : TrapezoidWeight A B) : 0 (physicalDiskCoordinates_mem hL.le p.2).mpr (hKd p hp)) have hIK : IsCompact (Ξ '' K) := hK.image hΞ.continuous obtain ⟨Ψ,Γ,δ,hδ,U,hU,hUK,hΨ,hΨ0,hΓ,hΓ0,hΨemb,hΓform⟩ := exists_actual_cubic_exact_family_with_zero (A := A) (B := B) D S (1/(L*Real.pi)) (hIK.image continuous_fst) (hIK.image continuous_snd) have hKU : MapsTo Ξ K U := by intro x hx exact hUK ⟨⟨Ξ x,⟨x,hx,rfl⟩,rfl⟩,⟨Ξ x,⟨x,hx,rfl⟩,rfl⟩⟩ let Δ : ℝ → ManifoldOneForm CubicPhysicalModel CubicPhysicalSpace := manifoldPullbackOneForm Γ Ξ have hΔ : SmoothOneFormFamily Δ := manifoldPullbackOneForm_smooth hΞ hΓ have hΔ0 (x : CubicPhysicalSpace) (hx : x∈V) : Δ 0 x= (productHorizontalLift (E := RealModel) (M := BaseCurve) (V := PlanePhase (Fin 2)) (physicalPrimitive (A := A) (B := B) D S (1/(L*Real.pi)) L ∘ planeMoments)+ (verticalLiouville : ManifoldOneForm CubicPhysicalModel CubicPhysicalSpace)) x := by have h := cubic_radial_primitive hA hAB D S hL hΞ hΞfst ((physicalDiskCoordinates_mem hL.le x.2).mp (hVd x hx)) (by filter_upwards [hV.mem_nhds hx] with y hy; exact hΞeq y hy) simpa only [Δ,manifoldPullbackOneForm,hΓ0] using h have hΔext (x : CubicPhysicalSpace) (hx : x∈V) : manifoldExteriorOneForm (Δ 0) x=cubicPhysicalForm (A := A) (B := B) D S L x := by apply coupling_exterior_of_primitive_germ (hΔ.comp (contDiff_const (c := (0:ℝ)))) filter_upwards [hV.mem_nhds hx] with y hy exact hΔ0 y hy have hnondeg (x : CubicPhysicalSpace) (hx : x∈K) : (manifoldExteriorOneForm (Δ 0) x).IsInvertible := by rw [hΔext x (hKV hx)] exact hinv x hx let F : ℝ × CubicPhysicalSpace → CubicAmbient := fun p => Ψ (p.1,Ξ p.2) have hF : ContMDiff ((𝓘(ℝ,ℝ)).prod 𝓘(ℝ,CubicPhysicalModel)) 𝓘(ℝ,CubicAmbient) ∞ F := hΨ.comp (contMDiff_fst.prodMk (hΞ.comp contMDiff_snd)) let O := V∩Ξ ⁻¹' U have hO : IsOpen O := hV.inter (hU.preimage hΞ.continuous) have hKO : K⊆O := fun x hx => ⟨hKV hx,hKU hx⟩ have htI {t : ℝ} (ht : t∈Ioc (0:ℝ) δ) : t∈Icc (-δ) δ := ⟨by linarith [ht.1],ht.2⟩ have hFemb (t : ℝ) (ht : t∈Ioc (0:ℝ) δ) : Topology.IsEmbedding (fun x : O => F (t,x.val)) := (hΨemb t (htI ht) (ne_of_gt ht.1)).comp (((hΞemb.comp (Topology.IsEmbedding.inclusion inter_subset_left)).codRestrict U) (fun x : O => x.property.2)) have hFform (t : ℝ) (ht : t∈Ioc (0:ℝ) δ) (x : CubicPhysicalSpace) (hx : x∈O) : manifoldExteriorOneForm (Δ t) x=(cubicAmbientForm (A := A) (B := B) D S (1/(L*Real.pi)) t (F (t,x))).bilinearComp (manifoldMapDifferential (E := CubicAmbient) (F := CubicPhysicalModel) (fun y => F (t,y)) x) (manifoldMapDifferential (E := CubicAmbient) (F := CubicPhysicalModel) (fun y => F (t,y)) x) := by have hs := hΨ.comp (contMDiff_const.prodMk contMDiff_id) (f := fun y : CubicConeSpace => (t,y)) have he := manifold_pullback_exterior (fun c y hy => (hΓ.spatial_smooth t c hy).contDiffWithinAt) hΞ x change manifoldExteriorOneForm (Δ t) x= (manifoldExteriorOneForm (Γ t) (Ξ x)).bilinearComp (manifoldMapDifferential (E := CubicConeModel) (F := CubicPhysicalModel) Ξ x) (manifoldMapDifferential (E := CubicConeModel) (F := CubicPhysicalModel) Ξ x) at he rw [he,hΓform t (htI ht) (ne_of_gt ht.1) (Ξ x) hx.2] have hdiff := manifoldMapDifferential_comp (hs.mdifferentiable (by simp) (Ξ x)) (hΞ.mdifferentiable (by simp) x) change manifoldMapDifferential (E := CubicAmbient) (F := CubicPhysicalModel) (fun y => F (t,y)) x=_ at hdiff rw [hdiff] rfl have hF0 : MapsTo (fun x => F (0,x)) K T := by intro x _hx change Ψ (0,Ξ x)∈T rw [hΨ0] exact hbase _ _ obtain ⟨t,ht,g,W,hW,hKW,hg,hgemb,hgT,hgform⟩ := exists_compact_exact_fibre_embedding_central_into hΔ hK hnondeg hO hKO hδ hF hFemb hT hF0 (fun t => cubicAmbientForm (A := A) (B := B) D S (1/(L*Real.pi)) t) hFform refine ⟨t,ht.1,g,W∩V,hW.inter hV,fun x hx => ⟨hKW hx,hKV hx⟩,hg, hgemb.comp (Topology.IsEmbedding.inclusion inter_subset_left),fun x hx => hgT hx.1,?_⟩ intro x hx v w have he := hgform x hx.1 v w rw [hΔext x hx.2] at he exact he theorem exists_actual_cubic_normal_transfer {A B : ℕ} (hA : 0 g x.val) ∧ ∀ x∈W,∀ v w,cubicAmbientForm (A := A) (B := B) D S (1/(L*Real.pi)) t (g x) (manifoldMapDifferential (E := CubicAmbient) (F := CubicPhysicalModel) g x v) (manifoldMapDifferential (E := CubicAmbient) (F := CubicPhysicalModel) g x w)= cubicPhysicalForm (A := A) (B := B) D S L x v w := by obtain ⟨t,ht,g,W,hW,hKW,hg,hgemb,_hgT,hgform⟩ := exists_actual_cubic_normal_transfer_into hA hAB D S hL hK hKd hinv isOpen_univ (fun _ _ => mem_univ _) exact ⟨t,ht,g,W,hW,hKW,hg,hgemb,hgform⟩ def cubicAffineDomain : Set CubicAmbient := {p | p.1.1≠0 ∧ p.1.2≠0} theorem cubicAffineDomain_isOpen : IsOpen cubicAffineDomain := (isOpen_ne_fun (continuous_fst.fst) continuous_const).inter (isOpen_ne_fun (continuous_fst.snd) continuous_const) theorem inclusion_mem_cubicAffineDomain (x : BaseCurve) (z : ℂ) : (inclusion x,z)∈cubicAffineDomain := ⟨inclusion_fst_ne_zero x,inclusion_snd_ne_zero x⟩ end PackingSufficiencySupport.CubicModel namespace PackingSufficiencySupport.Hamiltonian open scoped ContDiff Manifold Topology open Set Function Manifold theorem productForm_isInvertible {V : Type*} [NormedAddCommGroup V] [NormedSpace ℝ V] [FiniteDimensional ℝ V] {A : V →L[ℝ] V →L[ℝ] ℝ} (hA : A.IsInvertible) : (productForm A).IsInvertible := by have he : oneCovectorForm A 1 0=productForm A := by apply ContinuousLinearMap.ext intro v apply ContinuousLinearMap.ext intro w simp [oneCovectorForm_apply,productForm_apply,planarArea_apply] ring rw [←he] exact oneCovectorForm_isInvertible hA one_ne_zero 0 theorem successorStandardForm_isInvertible (m : ℕ) : (successorStandardForm m).IsInvertible := bilinearComp_equiv_isInvertible (complexSplitPhase m) (productForm_isInvertible phaseArea_isInvertible) theorem isInvertible_of_bilinearComp {E F : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E] [NormedAddCommGroup F] [NormedSpace ℝ F] [FiniteDimensional ℝ E] [FiniteDimensional ℝ F] (hdim : Module.finrank ℝ E=Module.finrank ℝ F) {A : F →L[ℝ] F →L[ℝ] ℝ} {L : E →L[ℝ] F} (h : (A.bilinearComp L L).IsInvertible) : A.IsInvertible := by obtain ⟨e,he⟩ := h have hL : Injective L := by apply (injective_iff_map_eq_zero L).mpr intro v hv apply e.injective change (e : E →L[ℝ] E →L[ℝ] ℝ) v=(e : E →L[ℝ] E →L[ℝ] ℝ) 0 rw [he] ext w simp [ContinuousLinearMap.bilinearComp_apply,hv] let c : E ≃L[ℝ] F := (L.toLinearMap.linearEquivOfInjective hL hdim).toContinuousLinearEquiv have hc : (c : E →L[ℝ] F)=L := by ext v; rfl apply (bilinearComp_equiv_isInvertible_iff c).mp rw [hc] exact ⟨e,he⟩ theorem FormNeighborhoodEmbedding.target_invertible {E F : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E] [NormedAddCommGroup F] [NormedSpace ℝ F] [FiniteDimensional ℝ E] [FiniteDimensional ℝ F] {M N : Type*} [TopologicalSpace M] [ChartedSpace E M] [TopologicalSpace N] [ChartedSpace F N] {K : Set N} {σ : ManifoldTwoForm F N} {Ω : ManifoldTwoForm E M} {f : N → M} (hf : FormNeighborhoodEmbedding K σ Ω f) (hdim : Module.finrank ℝ F=Module.finrank ℝ E) {x : N} (hx : x∈K) (hσ : (σ x).IsInvertible) : (Ω (f x)).IsInvertible := by obtain ⟨U,_hU,hKU,_hs,_he,hform⟩ := hf apply isInvertible_of_bilinearComp (E := F) (F := E) hdim (L := manifoldMapDifferential (E := E) (F := F) f x) have hh : (Ω (f x)).bilinearComp (manifoldMapDifferential (E := E) (F := F) f x) (manifoldMapDifferential (E := E) (F := F) f x)=σ x := by apply ContinuousLinearMap.ext intro v apply ContinuousLinearMap.ext intro w exact hform x (hKU hx) v w rw [hh] exact hσ end PackingSufficiencySupport.Hamiltonian end end OAI