Lean Ridgelet Blueprint

1. L2 theory: arXiv:2106.04770v2 implementation map🔗

This chapter follows the publication order and single shared theorem-like counter of arXiv:2106.04770v2. The paper first derives the separated Fourier expression in the Introduction, isolates its abstract unitary operator theory in Section 2, and only then constructs the concrete activation, coefficient, and parameter spaces. Later sections treat adjoint ridgelet functions, finite-width consequences, numerics, and parameter perturbations as distinct developments.

The Lean project completely implements the abstract unitary layer and its transported-coordinate specialization. A few concrete analytic identifications still stop at the coefficient-vector level; these boundaries are stated below rather than hidden behind assumptions. A declaration containing sorry records a later manuscript result whose proof is still pending and is checked by the assumption audit.

The Fourier expression method in Section 1.2 proposes \gamma^\sharp(\xi/\omega,\omega)=\widehat f(\xi)\overline{\rho^\sharp(\omega)} and separates one particular direction from homogeneous directions. Lean currently validates the resulting unitary-coordinate and Hilbert-basis theory. It also reconstructs a ridgelet distribution continuously from every completed coefficient vector, with the expected weighted spectrum on the dense Schwartz core. On the Schwartz compatibility domain, the synthesis and ridgelet operators now agree with the classical network and ridgelet integrals; the remaining classical boundaries are the explicit Fourier formulas (32)--(33) and per-activation realization formulas.

Section 2: Abstract Reconstruction Formula and Solution Geometry

Definition1
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Theorem 2
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L∃∀N

Let (X,\mu) be a measure space, let \mathcal H and \mathcal G be complex Hilbert spaces, let T:\mathcal G\simeq L^2(X,\mu;\mathcal H) be unitary, and let L:\mathcal H\to\mathbb C be continuous and linear. Define S:=\widetilde L\,T:\mathcal G\to L^2(X,\mu),\qquad R_h:=T^*J_h:L^2(X,\mu)\to\mathcal G,\qquad J_h[f](x):=f(x)h.

Lean code for Definition12 definitions
  • def LeanRidgelet.unitarySynthesis.{u_1, u_2, u_3} {α : Type u_1}
      {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [NormedAddCommGroup G] [InnerProductSpace  G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] ) :
      G →L[] (LeanRidgelet.L2 α μ)
    def LeanRidgelet.unitarySynthesis.{u_1, u_2,
        u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [NormedAddCommGroup G]
      [InnerProductSpace  G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] ) :
      G →L[] (LeanRidgelet.L2 α μ)
    Implementation after :=
    :=
      fiberSynthesis μ L ∘L (T : G →L[ℂ] BochnerL2 α H μ)
    The abstract synthesis operator `S = \widetilde L T`. 
  • def LeanRidgelet.unitaryRidgelet.{u_1, u_2, u_3} {α : Type u_1}
      {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [NormedAddCommGroup G] [InnerProductSpace  G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (h : H) :
      (LeanRidgelet.L2 α μ) →L[] G
    def LeanRidgelet.unitaryRidgelet.{u_1, u_2,
        u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [NormedAddCommGroup G]
      [InnerProductSpace  G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (h : H) : (LeanRidgelet.L2 α μ) →L[] G
    Implementation after :=
    :=
      (T.symm : BochnerL2 α H μ →L[ℂ] G) ∘L fiberRidgelet μ h
    The abstract ridgelet map `R_h = T* J_h`.  For a unitary equivalence, `T* = T⁻¹`. 
Theorem2
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L∃∀N

Under Definition 1, let h\in\mathcal H, let h_L be the Riesz vector determined by L[h]=\langle h,h_L\rangle, and put c_L:=\|h_L\|^2=\|L\|^2. Then S\circ R_h=L[h]I,\qquad S^*=R_{h_L},\qquad S\circ S^*=c_LI, \qquad \|S^*[f]\|^2=c_L\|f\|^2\quad(f\in L^2(X,\mu)). No hypothesis L\ne0 is required.

Lean code for Theorem24 theorems
  • complete
    theorem LeanRidgelet.unitarySynthesis_comp_unitaryRidgelet.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [NormedAddCommGroup G] [InnerProductSpace  G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] )
      (h : H) :
      LeanRidgelet.unitarySynthesis μ T L ∘SL
          LeanRidgelet.unitaryRidgelet μ T h =
        L h  ContinuousLinearMap.id  (LeanRidgelet.L2 α μ)
    theorem LeanRidgelet.unitarySynthesis_comp_unitaryRidgelet.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [NormedAddCommGroup G]
      [InnerProductSpace  G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] ) (h : H) :
      LeanRidgelet.unitarySynthesis μ T L ∘SL
          LeanRidgelet.unitaryRidgelet μ T h =
        L h 
          ContinuousLinearMap.id 
            (LeanRidgelet.L2 α μ)
    Abstract reconstruction: `S R_h = L[h] I`. 
  • complete
    theorem LeanRidgelet.adjoint_unitarySynthesis.{u_1, u_2, u_3} {α : Type u_1}
      {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] ) :
      ContinuousLinearMap.adjoint (LeanRidgelet.unitarySynthesis μ T L) =
        LeanRidgelet.unitaryRidgelet μ T (LeanRidgelet.rieszRepresenter L)
    theorem LeanRidgelet.adjoint_unitarySynthesis.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] ) :
      ContinuousLinearMap.adjoint
          (LeanRidgelet.unitarySynthesis μ T
            L) =
        LeanRidgelet.unitaryRidgelet μ T
          (LeanRidgelet.rieszRepresenter L)
    The adjoint of synthesis is the ridgelet map associated with the Riesz representer. 
  • complete
    theorem LeanRidgelet.unitarySynthesis_comp_adjoint.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] ) :
      LeanRidgelet.unitarySynthesis μ T L ∘SL
          ContinuousLinearMap.adjoint
            (LeanRidgelet.unitarySynthesis μ T L) =
        (LeanRidgelet.fiberNormalization L) 
          ContinuousLinearMap.id  (LeanRidgelet.L2 α μ)
    theorem LeanRidgelet.unitarySynthesis_comp_adjoint.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] ) :
      LeanRidgelet.unitarySynthesis μ T L ∘SL
          ContinuousLinearMap.adjoint
            (LeanRidgelet.unitarySynthesis μ T
              L) =
        (LeanRidgelet.fiberNormalization L) 
          ContinuousLinearMap.id 
            (LeanRidgelet.L2 α μ)
    Synthesis composed with its adjoint is scalar multiplication by `c_L`. 
  • complete
    theorem LeanRidgelet.norm_adjoint_unitarySynthesis_sq.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] )
      (f : (LeanRidgelet.L2 α μ)) :
      (ContinuousLinearMap.adjoint (LeanRidgelet.unitarySynthesis μ T L))
              f ^
          2 =
        LeanRidgelet.fiberNormalization L * f ^ 2
    theorem LeanRidgelet.norm_adjoint_unitarySynthesis_sq.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] )
      (f : (LeanRidgelet.L2 α μ)) :
      (ContinuousLinearMap.adjoint
                (LeanRidgelet.unitarySynthesis
                  μ T L))
              f ^
          2 =
        LeanRidgelet.fiberNormalization L *
          f ^ 2
    Exact norm identity for the abstract synthesis adjoint. 
Theorem3
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L∃∀N

Assume the data of Definition 1 and L\ne0. Define S^\dagger:=c_L^{-1}S^*,\qquad P:=S^\dagger S. Then SS^\dagger=I, P^2=P=P^*, and \ker P=\ker S,\qquad \operatorname{ran}P=(\ker S)^\perp, \qquad T[\ker S]=L^2(X,\mu;\ker L). Moreover, for f\in L^2(X,\mu) and \gamma\in\mathcal G, S[\gamma]=f\iff\gamma-S^\dagger[f]\in\ker S, and every such solution satisfies \|\gamma\|^2=\|S^\dagger[f]\|^2+\|\gamma-S^\dagger[f]\|^2. Thus S^\dagger[f] is the unique minimum-norm solution.

Lean code for Theorem311 declarations
  • def LeanRidgelet.unitaryMoorePenroseInverse.{u_1, u_2, u_3} {α : Type u_1}
      {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] ) :
      (LeanRidgelet.L2 α μ) →L[] G
    def LeanRidgelet.unitaryMoorePenroseInverse.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] ) :
      (LeanRidgelet.L2 α μ) →L[] G
    Implementation after :=
    :=
      ((fiberNormalization L : ℂ)⁻¹) • (unitarySynthesis μ T L)†
    The abstract Moore--Penrose inverse `S† = c_L⁻¹ S*` for nonzero `L`.
    
    Here the name `moorePenroseInverse` distinguishes it from Lean's postfix `†`, which denotes only
    the Hilbert adjoint. 
  • def LeanRidgelet.unitaryParameterProjection.{u_1, u_2, u_3} {α : Type u_1}
      {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] ) :
      G →L[] G
    def LeanRidgelet.unitaryParameterProjection.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] ) : G →L[] G
    Implementation after :=
    :=
      unitaryMoorePenroseInverse μ T L ∘L unitarySynthesis μ T L
    The canonical parameter projection `P = S† S`. 
  • complete
    theorem LeanRidgelet.unitaryMoorePenroseInverse_rightInverse.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) {L : H →L[] }
      (hL : L  0) :
      Function.RightInverse (LeanRidgelet.unitaryMoorePenroseInverse μ T L)
        (LeanRidgelet.unitarySynthesis μ T L)
    theorem LeanRidgelet.unitaryMoorePenroseInverse_rightInverse.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      {L : H →L[] } (hL : L  0) :
      Function.RightInverse
        (LeanRidgelet.unitaryMoorePenroseInverse
            μ T L)
        (LeanRidgelet.unitarySynthesis μ T L)
    For nonzero `L`, the Moore--Penrose inverse is a right inverse of synthesis. 
  • complete
    theorem LeanRidgelet.isIdempotentElem_unitaryParameterProjection.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) {L : H →L[] }
      (hL : L  0) :
      IsIdempotentElem (LeanRidgelet.unitaryParameterProjection μ T L)
    theorem LeanRidgelet.isIdempotentElem_unitaryParameterProjection.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      {L : H →L[] } (hL : L  0) :
      IsIdempotentElem
        (LeanRidgelet.unitaryParameterProjection
          μ T L)
  • complete
    theorem LeanRidgelet.isSelfAdjoint_unitaryParameterProjection.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] ) :
      IsSelfAdjoint (LeanRidgelet.unitaryParameterProjection μ T L)
    theorem LeanRidgelet.isSelfAdjoint_unitaryParameterProjection.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] ) :
      IsSelfAdjoint
        (LeanRidgelet.unitaryParameterProjection
          μ T L)
  • complete
    theorem LeanRidgelet.ker_unitaryParameterProjection.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) {L : H →L[] }
      (hL : L  0) :
      (↑(LeanRidgelet.unitaryParameterProjection μ T L)).ker =
        (↑(LeanRidgelet.unitarySynthesis μ T L)).ker
    theorem LeanRidgelet.ker_unitaryParameterProjection.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      {L : H →L[] } (hL : L  0) :
      (↑(LeanRidgelet.unitaryParameterProjection
              μ T L)).ker =
        (↑(LeanRidgelet.unitarySynthesis μ T
              L)).ker
    The kernel of the canonical parameter projection is the synthesis kernel. 
  • complete
    theorem LeanRidgelet.range_unitaryParameterProjection.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) {L : H →L[] }
      (hL : L  0) :
      (↑(LeanRidgelet.unitaryParameterProjection μ T L)).range =
        (↑(LeanRidgelet.unitarySynthesis μ T L)).ker
    theorem LeanRidgelet.range_unitaryParameterProjection.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      {L : H →L[] } (hL : L  0) :
      (↑(LeanRidgelet.unitaryParameterProjection
              μ T L)).range =
        (↑(LeanRidgelet.unitarySynthesis μ T
                L)).ker
    The range of the canonical projection is the orthogonal complement of the synthesis kernel. 
  • complete
    theorem LeanRidgelet.map_ker_unitarySynthesis.{u_1, u_2, u_3} {α : Type u_1}
      {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [NormedAddCommGroup G] [InnerProductSpace  G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] ) :
      Submodule.map (↑T.toLinearEquiv)
          (↑(LeanRidgelet.unitarySynthesis μ T L)).ker =
        (↑(LeanRidgelet.fiberSynthesis μ L)).ker
    theorem LeanRidgelet.map_ker_unitarySynthesis.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [NormedAddCommGroup G]
      [InnerProductSpace  G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] ) :
      Submodule.map (↑T.toLinearEquiv)
          (↑(LeanRidgelet.unitarySynthesis μ T
                L)).ker =
        (↑(LeanRidgelet.fiberSynthesis μ
              L)).ker
    Unitary coordinates identify the synthesis kernel with the coordinate-side pointwise kernel. 
  • complete
    theorem LeanRidgelet.unitarySolution_iff_kernel_translate.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) {L : H →L[] }
      (hL : L  0) (f : (LeanRidgelet.L2 α μ)) (γ : G) :
      (LeanRidgelet.unitarySynthesis μ T L) γ = f 
        γ - (LeanRidgelet.unitaryMoorePenroseInverse μ T L) f 
          (↑(LeanRidgelet.unitarySynthesis μ T L)).ker
    theorem LeanRidgelet.unitarySolution_iff_kernel_translate.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      {L : H →L[] } (hL : L  0)
      (f : (LeanRidgelet.L2 α μ)) (γ : G) :
      (LeanRidgelet.unitarySynthesis μ T L)
            γ =
          f 
        γ -
            (LeanRidgelet.unitaryMoorePenroseInverse
                μ T L)
              f 
          (↑(LeanRidgelet.unitarySynthesis μ T
                L)).ker
    Every solution is the canonical solution plus an element of the synthesis kernel. 
  • complete
    theorem LeanRidgelet.unitaryMoorePenroseInverse_pythagorean.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) {L : H →L[] }
      (hL : L  0) (f : (LeanRidgelet.L2 α μ)) (γ : G)
      ( : (LeanRidgelet.unitarySynthesis μ T L) γ = f) :
      γ ^ 2 =
        (LeanRidgelet.unitaryMoorePenroseInverse μ T L) f ^ 2 +
          γ - (LeanRidgelet.unitaryMoorePenroseInverse μ T L) f ^ 2
    theorem LeanRidgelet.unitaryMoorePenroseInverse_pythagorean.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      {L : H →L[] } (hL : L  0)
      (f : (LeanRidgelet.L2 α μ)) (γ : G)
      ( :
        (LeanRidgelet.unitarySynthesis μ T L)
            γ =
          f) :
      γ ^ 2 =
        (LeanRidgelet.unitaryMoorePenroseInverse
                  μ T L)
                f ^
            2 +
          γ -
                (LeanRidgelet.unitaryMoorePenroseInverse
                    μ T L)
                  f ^
            2
    Pythagoras identity for the abstract parameter-space solution decomposition. 
  • complete
    theorem LeanRidgelet.unitaryMoorePenroseInverse_unique_minimal.{u_1, u_2, u_3}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] [CompleteSpace G]
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) {L : H →L[] }
      (hL : L  0) (f : (LeanRidgelet.L2 α μ)) (γ : G) :
      (LeanRidgelet.unitarySynthesis μ T L) γ = f 
        (LeanRidgelet.unitaryMoorePenroseInverse μ T L) f  γ 
          ((LeanRidgelet.unitaryMoorePenroseInverse μ T L) f = γ 
            (LeanRidgelet.unitaryMoorePenroseInverse μ T L) f = γ)
    theorem LeanRidgelet.unitaryMoorePenroseInverse_unique_minimal.{u_1,
        u_2, u_3}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G]
      [CompleteSpace G]
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      {L : H →L[] } (hL : L  0)
      (f : (LeanRidgelet.L2 α μ)) (γ : G) :
      (LeanRidgelet.unitarySynthesis μ T L)
            γ =
          f 
        (LeanRidgelet.unitaryMoorePenroseInverse
                  μ T L)
                f 
            γ 
          ((LeanRidgelet.unitaryMoorePenroseInverse
                    μ T L)
                  f =
              γ 
            (LeanRidgelet.unitaryMoorePenroseInverse
                  μ T L)
                f =
              γ)
    The abstract Moore--Penrose solution is the unique minimum-norm solution. 
Theorem4
uses 1used by 1L∃∀N

Assume Definition 1 and let (e_i)_{i\in I} be a Hilbert basis of L^2(X,\mu). For \gamma\in\mathcal G, define h_i[\gamma]\in\mathcal H by the partial inner product of T[\gamma] against e_i. Then \gamma=\sum_{i\in I}R_{h_i[\gamma]}[e_i],\qquad \sum_{i\in I}\|h_i[\gamma]\|^2=\|\gamma\|^2, and these coefficient vectors are unique. Furthermore, \gamma\in\ker S\iff(\forall i\in I)\;h_i[\gamma]\in\ker L. If (k_j)_{j\in J} is a Hilbert basis of \ker L, every \gamma\in\ker S also has the unconditionally convergent expansion \gamma=\sum_{(i,j)\in I\times J}c_{ij}\,R_{k_j}[e_i], \qquad(c_{ij})\in\ell^2(I\times J).

Lean code for Theorem46 declarations
  • complete
    theorem LeanRidgelet.hasSum_unitaryRidgelet_coefficients.{u_1, u_2, u_3, u_4}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ))
      (b : HilbertBasis ι  (LeanRidgelet.L2 α μ)) (γ : G) :
      HasSum
        (fun i 
          (LeanRidgelet.unitaryRidgelet μ T
              (LeanRidgelet.unitaryCoefficient μ T (b i) γ))
            (b i))
        γ
    theorem LeanRidgelet.hasSum_unitaryRidgelet_coefficients.{u_1,
        u_2, u_3, u_4}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (b :
        HilbertBasis ι 
          (LeanRidgelet.L2 α μ))
      (γ : G) :
      HasSum
        (fun i 
          (LeanRidgelet.unitaryRidgelet μ T
              (LeanRidgelet.unitaryCoefficient
                μ T (b i) γ))
            (b i))
        γ
    Hilbert-basis expansion in the abstract parameter space. 
  • complete
    theorem LeanRidgelet.eq_unitaryCoefficient_of_hasSum_unitaryRidgelet.{u_1, u_2,
        u_3, u_4}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ))
      (b : HilbertBasis ι  (LeanRidgelet.L2 α μ)) (h : ι  H) (γ : G)
      (hq :
        HasSum (fun i  (LeanRidgelet.unitaryRidgelet μ T (h i)) (b i)) γ)
      (i : ι) : h i = LeanRidgelet.unitaryCoefficient μ T (b i) γ
    theorem LeanRidgelet.eq_unitaryCoefficient_of_hasSum_unitaryRidgelet.{u_1,
        u_2, u_3, u_4}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (b :
        HilbertBasis ι 
          (LeanRidgelet.L2 α μ))
      (h : ι  H) (γ : G)
      (hq :
        HasSum
          (fun i 
            (LeanRidgelet.unitaryRidgelet μ T
                (h i))
              (b i))
          γ)
      (i : ι) :
      h i =
        LeanRidgelet.unitaryCoefficient μ T
          (b i) γ
    Coefficient vectors in the unitary ridgelet expansion are unique. 
  • complete
    theorem LeanRidgelet.hasSum_norm_sq_unitaryCoefficient.{u_1, u_2, u_3, u_4}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ))
      (b : HilbertBasis ι  (LeanRidgelet.L2 α μ)) (γ : G) :
      HasSum (fun i  LeanRidgelet.unitaryCoefficient μ T (b i) γ ^ 2)
        (γ ^ 2)
    theorem LeanRidgelet.hasSum_norm_sq_unitaryCoefficient.{u_1,
        u_2, u_3, u_4}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (b :
        HilbertBasis ι 
          (LeanRidgelet.L2 α μ))
      (γ : G) :
      HasSum
        (fun i 
          LeanRidgelet.unitaryCoefficient μ T
                (b i) γ ^
            2)
        (γ ^ 2)
    Parseval identity for coefficient vectors in the abstract parameter space. 
  • complete
    theorem LeanRidgelet.mem_ker_unitarySynthesis_iff_coefficients.{u_1, u_2, u_3,
        u_4}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] )
      (b : HilbertBasis ι  (LeanRidgelet.L2 α μ)) (γ : G) :
      γ  (↑(LeanRidgelet.unitarySynthesis μ T L)).ker 
         (i : ι), L (LeanRidgelet.unitaryCoefficient μ T (b i) γ) = 0
    theorem LeanRidgelet.mem_ker_unitarySynthesis_iff_coefficients.{u_1,
        u_2, u_3, u_4}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] )
      (b :
        HilbertBasis ι 
          (LeanRidgelet.L2 α μ))
      (γ : G) :
      γ 
          (↑(LeanRidgelet.unitarySynthesis μ T
                L)).ker 
         (i : ι),
          L
              (LeanRidgelet.unitaryCoefficient
                μ T (b i) γ) =
            0
    A parameter is null exactly when every Hilbert-basis coefficient lies in `ker L`. 
  • def LeanRidgelet.unitaryNullDoubleCoefficients.{u_1, u_2, u_3, u_4, u_5}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4} {κ : Type u_5}
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] )
      (b : HilbertBasis ι  (LeanRidgelet.L2 α μ))
      (d : HilbertBasis κ  (↑L).ker) (γ : G)
      ( : γ  (↑(LeanRidgelet.unitarySynthesis μ T L)).ker) :
      (lp (fun x  ) 2)
    def LeanRidgelet.unitaryNullDoubleCoefficients.{u_1,
        u_2, u_3, u_4, u_5}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      {κ : Type u_5}
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] )
      (b :
        HilbertBasis ι 
          (LeanRidgelet.L2 α μ))
      (d : HilbertBasis κ  (↑L).ker) (γ : G)
      ( :
        γ 
          (↑(LeanRidgelet.unitarySynthesis μ T
                L)).ker) :
      (lp (fun x  ) 2)
    Implementation after :=
    :=
      fiberNullDoubleCoefficients μ L b d (T γ) (by
        change fiberSynthesis μ L (T γ) = 0
        exact hγ)
    The flattened null coefficients of an abstract parameter as an element of `ℓ²(I × J)`. 
  • complete
    theorem LeanRidgelet.hasSum_unitaryRidgelet_kernelBasis.{u_1, u_2, u_3, u_4,
        u_5}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4} {κ : Type u_5}
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] )
      (b : HilbertBasis ι  (LeanRidgelet.L2 α μ))
      (d : HilbertBasis κ  (↑L).ker) (γ : G)
      ( : γ  (↑(LeanRidgelet.unitarySynthesis μ T L)).ker) :
      HasSum
        (fun p 
          (LeanRidgelet.unitaryNullDoubleCoefficients μ T L b d γ ) p 
            (LeanRidgelet.unitaryRidgelet μ T (d p.2)) (b p.1))
        γ
    theorem LeanRidgelet.hasSum_unitaryRidgelet_kernelBasis.{u_1,
        u_2, u_3, u_4, u_5}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      {κ : Type u_5}
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] )
      (b :
        HilbertBasis ι 
          (LeanRidgelet.L2 α μ))
      (d : HilbertBasis κ  (↑L).ker) (γ : G)
      ( :
        γ 
          (↑(LeanRidgelet.unitarySynthesis μ T
                L)).ker) :
      HasSum
        (fun p 
          (LeanRidgelet.unitaryNullDoubleCoefficients
                  μ T L b d γ )
              p 
            (LeanRidgelet.unitaryRidgelet μ T
                (d p.2))
              (b p.1))
        γ
    Every abstract null parameter has the unconditional `I × J` ridgelet expansion associated
    with Hilbert bases of `L²(X)` and `ker L`. 

Section 3: Neural-Network Specialization: Hilbert Spaces and Boundedness

Definition5
uses 0
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L∃∀N

For s,t\in\mathbb R, define the activation space \mathcal A_{s,t}:=\langle\cdot\rangle^tH^s(\mathbb R), represented by its Fourier--Bessel coordinate u\in L^2(\mathbb R). In Lean, the coordinate Hilbert space determines the associated tempered distribution \sigma=\langle\cdot\rangle^t\langle\partial\rangle^{-s}[u].

Lean code for Definition52 definitions
  • complete
    abbrev LeanRidgelet.ActivationSpace (_s _t : ) :
      AddSubgroup ( →ₘ[MeasureTheory.volume] )
    abbrev LeanRidgelet.ActivationSpace (_s _t : ) :
      AddSubgroup
        ( →ₘ[MeasureTheory.volume] )
    Implementation after :=
    := L2 ℝ volume
    The Hilbert coordinate model of the activation space `A_{s,t}`. 
  • complete
    def LeanRidgelet.activationDistribution (s t : ) :
      (LeanRidgelet.ActivationSpace s t) →L[] TemperedDistribution  
    def LeanRidgelet.activationDistribution
      (s t : ) :
      (LeanRidgelet.ActivationSpace s
            t) →L[]
        TemperedDistribution  
    Implementation after :=
    :=
      temperedWeightMultiplier t ∘L
        paperBesselPotential (-s) ∘L
          Lp.toTemperedDistributionCLM ℂ volume 2
    Realize an activation coordinate as an element of `⟨·⟩^t H^s(ℝ) ⊆ 𝓢'(ℝ)`. 
Proposition6
uses 1used by 0L∃∀N

For every s,t\in\mathbb R, the coordinate map of Definition 5 is a linear isometric equivalence \mathcal A_{s,t}\simeq L^2(\mathbb R). Consequently \mathcal A_{s,t} is a complex Hilbert space.

Lean code for Proposition61 theorem
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    complete
    theorem LeanRidgelet.l2_proposition_one_activation_hilbert_structure (s t : ) :
      Nonempty
        ((LeanRidgelet.ActivationSpace s t) ≃ₗᵢ[]
          (LeanRidgelet.L2  MeasureTheory.volume))
    theorem LeanRidgelet.l2_proposition_one_activation_hilbert_structure
      (s t : ) :
      Nonempty
        ((LeanRidgelet.ActivationSpace s
              t) ≃ₗᵢ[]
          (LeanRidgelet.L2 
              MeasureTheory.volume))
    Manuscript Proposition 6: the activation coordinate map is an
    isometric isomorphism onto `L²(ℝ)`. 
Definition7
uses 0
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L∃∀N

Let m\ge1 and s,t\in\mathbb R. For h\in\mathcal S(\mathbb R), define \|h\|_{\mathcal H_{s,t}}^2:=C_m\int_{\mathbb R}|h(\omega)|^2|\omega|^m\,d\omega +\int_{\mathbb R}|\langle\partial_\omega\rangle^t[h](\omega)|^2 \langle\omega\rangle^{-2s}\,d\omega. The coefficient space \mathcal H_{s,t} is the Hilbert completion of this normed core. Every completed h\in\mathcal H_{s,t} has a tempered-distribution realization that equals the original Schwartz function on the dense core.

Lean code for Definition74 declarations
  • complete
    def LeanRidgelet.fiberNormSq (m : ) (s t : ) (h : SchwartzMap  ) : 
    def LeanRidgelet.fiberNormSq (m : ) (s t : )
      (h : SchwartzMap  ) : 
    Implementation after :=
    :=
      fiberBaseNormSq m h + fiberSobolevNormSq s t h
    The squared norm on the Schwartz core of `H_{s,t}`, before Hilbert completion. 
  • complete
    abbrev LeanRidgelet.FiberSpace (m : ) [NeZero m] (s t : ) : Type
    abbrev LeanRidgelet.FiberSpace (m : ) [NeZero m]
      (s t : ) : Type
    Implementation after :=
    :=
      UniformSpace.Completion (FiberCore m s t)
    The fiber Hilbert space `H_{s,t}`, defined as the completion of its Schwartz core. 
  • def LeanRidgelet.fiberDistribution (m : ) [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L[] TemperedDistribution  
    def LeanRidgelet.fiberDistribution (m : )
      [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L[]
        TemperedDistribution  
    Implementation after :=
    :=
      paperBesselPotential (-t) ∘L
        temperedWeightMultiplier s ∘L
          Lp.toTemperedDistributionCLM ℂ volume 2 ∘L
            fiberDualCoordinate m s t
    Realize a completed coefficient vector as a tempered distribution by undoing its weighted
    Bessel coordinate.  This is the distributional realization needed before constructing the
    manuscript ridgelet function `ρ` from its coefficient vector `hρ`. 
  • complete
    theorem LeanRidgelet.fiberDistribution_coe (m : ) [NeZero m] (s t : )
      (h : LeanRidgelet.FiberCore m s t) :
      (LeanRidgelet.fiberDistribution m s t) h =
        (SchwartzMap.toTemperedDistributionCLM   MeasureTheory.volume)
          h.toSchwartz
    theorem LeanRidgelet.fiberDistribution_coe (m : )
      [NeZero m] (s t : )
      (h : LeanRidgelet.FiberCore m s t) :
      (LeanRidgelet.fiberDistribution m s t)
          h =
        (SchwartzMap.toTemperedDistributionCLM
              MeasureTheory.volume)
          h.toSchwartz
    On the dense Schwartz core, the completed coefficient-distribution realization recovers the
    original Schwartz function as a tempered distribution. 
Definition8
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L∃∀N

Let m\ge1, s,t\in\mathbb R, and \sigma\in\mathcal A_{s,t}. Define the spectrum \sigma^\sharp:=\texttt{activationSpectrum}(\sigma) and its inverse-Fourier realization \sigma_{\mathrm{cl}}:=\mathcal F^{-1}[\sigma^\sharp]. Then the pairing extends uniquely to a continuous linear functional L_\sigma:\mathcal H_{s,t}\to\mathbb C with \|L_\sigma\|\le(2\pi)^{m-1}\|\sigma\|_{\mathcal A_{s,t}},\qquad L_\sigma[h]=(2\pi)^{m-1}\sigma^\sharp[h] for every Schwartz-core coefficient h.

Lean code for Definition85 declarations
  • complete
    def LeanRidgelet.activationFiberFunctional (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.FiberSpace m s t →L[] 
    def LeanRidgelet.activationFiberFunctional
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.FiberSpace m s t →L[] 
    Implementation after :=
    :=
      ((2 * Real.pi : ℂ) ^ (m - 1)) •
        ((innerSL ℂ (star σ)).comp (fiberDualCoordinate m s t))
    The activation-induced functional `L_σ` on the coefficient Hilbert space. 
  • complete
    def LeanRidgelet.activationSpectrum (s t : ) :
      (LeanRidgelet.ActivationSpace s t) →L[] TemperedDistribution  
    def LeanRidgelet.activationSpectrum
      (s t : ) :
      (LeanRidgelet.ActivationSpace s
            t) →L[]
        TemperedDistribution  
    Implementation after :=
    :=
      paperBesselPotential t ∘L
        temperedWeightMultiplier (-s) ∘L
          Lp.toTemperedDistributionCLM ℂ volume 2
    The manuscript activation spectrum `σ♯ = ⟨∂ω⟩^t[⟨ω⟩^{-s} σ]`, reconstructed from the
    `L²` activation coordinate `σ = ⟨ω⟩^s ⟨∂ω⟩^{-t}[σ♯]`. 
  • complete
    def LeanRidgelet.activationRealization (s t : ) :
      (LeanRidgelet.ActivationSpace s t) →L[] TemperedDistribution  
    def LeanRidgelet.activationRealization
      (s t : ) :
      (LeanRidgelet.ActivationSpace s
            t) →L[]
        TemperedDistribution  
    Implementation after :=
    :=
      paperFourierInvDistribution ∘L activationSpectrum s t
    The classical activation `σ = 𝓕⁻¹_paper[σ♯]`, realized as a tempered distribution from the
    activation coordinate.  This is the activation whose network the synthesis operator actually
    computes; compare `activationDistribution`, which realizes the same coordinate through the
    real-domain weighted Sobolev isometry instead. 
  • theorem LeanRidgelet.activationSpectrum_apply (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) (h : SchwartzMap  ) :
      ((LeanRidgelet.activationSpectrum s t) σ) h =
        inner  (star σ) (LeanRidgelet.fiberDualCoordinateCoreValue s t h)
    theorem LeanRidgelet.activationSpectrum_apply
      (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (h : SchwartzMap  ) :
      ((LeanRidgelet.activationSpectrum s t)
            σ)
          h =
        inner  (star σ)
          (LeanRidgelet.fiberDualCoordinateCoreValue
            s t h)
    The activation spectrum acts on a Schwartz coefficient vector by the weighted dual pairing.
    This identity is the content of the manuscript's self-adjoint rewrite of `∫ h σ♯`. 
  • theorem LeanRidgelet.activationFiberFunctional_eq_spectrum (m : ) [NeZero m]
      (s t : ) (σ : (LeanRidgelet.ActivationSpace s t))
      (h : LeanRidgelet.FiberCore m s t) :
      (LeanRidgelet.activationFiberFunctional m s t σ) h =
        (2 * Real.pi) ^ (m - 1) *
          ((LeanRidgelet.activationSpectrum s t) σ) h.toSchwartz
    theorem LeanRidgelet.activationFiberFunctional_eq_spectrum
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (h : LeanRidgelet.FiberCore m s t) :
      (LeanRidgelet.activationFiberFunctional
            m s t σ)
          h =
        (2 * Real.pi) ^ (m - 1) *
          ((LeanRidgelet.activationSpectrum s
                t)
              σ)
            h.toSchwartz
    On the Schwartz fiber core, the activation functional is `(2π)^{m-1}` times the
    distributional action of the manuscript spectrum `σ♯`.  This proves the Blueprint formula
    `L_σ[h] = (2π)^{m-1} ∫ h(ω) σ♯(ω) dω` for the transported coordinate model. 
Definition9
uses 0
Used by 2
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L∃∀N

Let m\ge1, s,t\in\mathbb R, and \gamma\in\mathcal S(\mathbb R^m\times\mathbb R). Define T_{\mathrm{pt}}[\gamma](x,\omega):=(2\pi)^{-m} \int_{\mathbb R^m\times\mathbb R}\gamma(a,b)e^{i\omega(a\cdot x-b)}\,da\,db. For each x, the function \omega\mapsto T_{\mathrm{pt}}[\gamma](x,\omega) is bundled as a coefficient-core vector. If this fiber-valued map belongs to Bochner L^2, it determines an element of the completed coordinate and parameter spaces.

Lean code for Definition94 definitions
  • def LeanRidgelet.fourierDilationTransformCore {m : }
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      (x : LeanRidgelet.InputSpace m) (ω : ) : 
    def LeanRidgelet.fourierDilationTransformCore
      {m : }
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      (x : LeanRidgelet.InputSpace m)
      (ω : ) : 
    Implementation after :=
    :=
      ((2 * Real.pi : ℂ) ^ m)⁻¹ *
        ∫ p : InputSpace m × ℝ, γ p * fourierDilationKernel x ω p
    The Fourier construction of `T` on Schwartz parameter distributions, before Hilbert-space
    extension. 
  • def LeanRidgelet.fourierDilationTransformFiberCore {m : } [NeZero m]
      (s t : ) (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      (x : LeanRidgelet.InputSpace m) : LeanRidgelet.FiberCore m s t
    def LeanRidgelet.fourierDilationTransformFiberCore
      {m : } [NeZero m] (s t : )
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      (x : LeanRidgelet.InputSpace m) :
      LeanRidgelet.FiberCore m s t
    Implementation after :=
    :=
      ((2 * Real.pi : ℂ) ^ m)⁻¹ •
        SchwartzMap.compCLMOfAntilipschitz ℂ (by fun_prop)
          antilipschitzWith_paperFrequencyScale (parameterFourierRestriction γ x)
    The integral Fourier--dilation formula, bundled as an element of the Schwartz fiber core. 
  • def LeanRidgelet.fourierDilationTransformCoreL2 {m : } [NeZero m] (s t : )
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber s t γ) 2
          MeasureTheory.volume) :
      (LeanRidgelet.BochnerL2 (LeanRidgelet.InputSpace m)
          (LeanRidgelet.FiberSpace m s t) MeasureTheory.volume)
    def LeanRidgelet.fourierDilationTransformCoreL2
      {m : } [NeZero m] (s t : )
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber
            s t γ)
          2 MeasureTheory.volume) :
      (LeanRidgelet.BochnerL2
          (LeanRidgelet.InputSpace m)
          (LeanRidgelet.FiberSpace m s t)
          MeasureTheory.volume)
    Implementation after :=
    :=
      hγ.toLp (fourierDilationTransformFiber s t γ)
    Bundle the fiber-valued core formula as a Bochner `L²` coordinate once its analytic
    membership has been established. 
  • def LeanRidgelet.parameterSchwartzRealization {m : } [NeZero m] (s t : )
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber s t γ) 2
          MeasureTheory.volume) :
      (LeanRidgelet.ParameterSpace m s t)
    def LeanRidgelet.parameterSchwartzRealization
      {m : } [NeZero m] (s t : )
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber
            s t γ)
          2 MeasureTheory.volume) :
      (LeanRidgelet.ParameterSpace m s t)
    Implementation after :=
    :=
      inverseFourierDilationTransform m s t (fourierDilationTransformCoreL2 s t γ hγ)
    The parameter-space element represented by a concrete Schwartz core formula whose
    fiber-valued transform belongs to Bochner `L²`. This uses the inverse transported unitary rather
    than storing membership as a field of a new assumption object. 
Lemma10
uses 1used by 1L∃∀N

Let m\ge1 and let g:\mathbb R^m\times\mathbb R\to[0,\infty] be Borel measurable. Then \int g(a,\omega)\,da\,d\omega=\int g(-\omega x,\omega)|\omega|^m\,dx\,d\omega. The exceptional slice \omega=0 is handled measure-theoretically rather than by claiming a globally invertible change of variables.

Lean code for Lemma101 theorem
  • complete
    theorem LeanRidgelet.integral_fourierDilationCoordinate_mul {m : } [NeZero m]
      (f : LeanRidgelet.InputSpace m ×   )
      (hf : MeasureTheory.Integrable f MeasureTheory.volume)
      (hf_cont : Continuous f) :
       (z : LeanRidgelet.InputSpace m × ), f z =
         (z : LeanRidgelet.InputSpace m × ),
          f (LeanRidgelet.fourierDilationCoordinate z.1 z.2) * |z.2| ^ m
    theorem LeanRidgelet.integral_fourierDilationCoordinate_mul
      {m : } [NeZero m]
      (f : LeanRidgelet.InputSpace m ×   )
      (hf :
        MeasureTheory.Integrable f
          MeasureTheory.volume)
      (hf_cont : Continuous f) :
       (z : LeanRidgelet.InputSpace m × ),
          f z =
         (z : LeanRidgelet.InputSpace m × ),
          f
              (LeanRidgelet.fourierDilationCoordinate
                z.1 z.2) *
            |z.2| ^ m
    Weighted dilation change of variables in integral form. This is the identity obtained by
    pushing `|ω|^m dx dω` forward along `(x, ω) ↦ (-ωx, ω)`. It does not require global
    injectivity: the exceptional fiber `ω = 0` is null, and the remaining fibers use Haar-measure
    scaling. 
Definition11
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used by 1L∃∀N

Let m\ge1 and s,t\in\mathbb R. Define the parameter Hilbert space and its coordinate map by \mathcal G_{s,t}:=L^2(\mathbb R^m;\mathcal H_{s,t}),\qquad T:\mathcal G_{s,t}\simeq L^2(\mathbb R^m;\mathcal H_{s,t}). The Lean parameter space is this transported coordinate model. Its identification with the manuscript's concrete graph domain is treated separately on the compatibility domain.

Lean code for Definition114 definitions
  • complete
    abbrev LeanRidgelet.ParameterSpace (m : ) [NeZero m] (s t : ) :
      AddSubgroup
        (LeanRidgelet.InputSpace m →ₘ[MeasureTheory.volume]
          LeanRidgelet.FiberSpace m s t)
    abbrev LeanRidgelet.ParameterSpace (m : )
      [NeZero m] (s t : ) :
      AddSubgroup
        (LeanRidgelet.InputSpace
            m →ₘ[MeasureTheory.volume]
          LeanRidgelet.FiberSpace m s t)
    Implementation after :=
    :=
      BochnerL2 (InputSpace m) (FiberSpace m s t) volume
    The coordinate model `L²(ℝᵐ; H_{s,t})` of the parameter Hilbert space. 
  • complete
    def LeanRidgelet.parameterCoordinateEquiv (m : ) [NeZero m] (s t : ) :
      (LeanRidgelet.ParameterSpace m s t) ≃ₗᵢ[]
        (LeanRidgelet.BochnerL2 (LeanRidgelet.InputSpace m)
            (LeanRidgelet.FiberSpace m s t) MeasureTheory.volume)
    def LeanRidgelet.parameterCoordinateEquiv
      (m : ) [NeZero m] (s t : ) :
      (LeanRidgelet.ParameterSpace m s
            t) ≃ₗᵢ[]
        (LeanRidgelet.BochnerL2
            (LeanRidgelet.InputSpace m)
            (LeanRidgelet.FiberSpace m s t)
            MeasureTheory.volume)
    Implementation after :=
    :=
      LinearIsometryEquiv.refl ℂ _
    The parameter-space unitary, with the source defined by transport to its Bochner `L²` model. 
  • def LeanRidgelet.fourierDilationTransform (m : ) [NeZero m] (s t : ) :
      (LeanRidgelet.ParameterSpace m s t) ≃ₗᵢ[]
        (LeanRidgelet.BochnerL2 (LeanRidgelet.InputSpace m)
            (LeanRidgelet.FiberSpace m s t) MeasureTheory.volume)
    def LeanRidgelet.fourierDilationTransform
      (m : ) [NeZero m] (s t : ) :
      (LeanRidgelet.ParameterSpace m s
            t) ≃ₗᵢ[]
        (LeanRidgelet.BochnerL2
            (LeanRidgelet.InputSpace m)
            (LeanRidgelet.FiberSpace m s t)
            MeasureTheory.volume)
    Implementation after :=
    :=
      parameterCoordinateEquiv m s t
    The unitary coordinate transform `T` in the transported coordinate model. 
  • def LeanRidgelet.inverseFourierDilationTransform (m : ) [NeZero m]
      (s t : ) :
      (LeanRidgelet.BochnerL2 (LeanRidgelet.InputSpace m)
            (LeanRidgelet.FiberSpace m s t) MeasureTheory.volume) ≃ₗᵢ[]
        (LeanRidgelet.ParameterSpace m s t)
    def LeanRidgelet.inverseFourierDilationTransform
      (m : ) [NeZero m] (s t : ) :
      (LeanRidgelet.BochnerL2
            (LeanRidgelet.InputSpace m)
            (LeanRidgelet.FiberSpace m s t)
            MeasureTheory.volume) ≃ₗᵢ[]
        (LeanRidgelet.ParameterSpace m s t)
    Implementation after :=
    :=
      (fourierDilationTransform m s t).symm
    The Hilbert-space inverse `T⁻¹ = T*`; the test-function Fourier expression is given below. 
Proposition12
uses 1
Used by 2
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Definition 13
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L∃∀N

Let m\ge1, s,t\in\mathbb R, and let T be Definition 11. Then T is unitary and T^{-1}T=I. If \gamma\in\mathcal S(\mathbb R^m\times\mathbb R) satisfies T_{\mathrm{pt}}[\gamma]\in L^2(\mathbb R^m;\mathcal H_{s,t}), then T[\gamma]=T_{\mathrm{pt}}[\gamma]\quad\text{a.e.} after embedding \gamma in \mathcal G_{s,t}. The inverse core is T^{-1}_{\mathrm{pt}}[u](a,b)=\frac1{2\pi}\int u(x,\omega) e^{-i\omega(a\cdot x-b)}|\omega|^m\,dx\,d\omega. Equality of the last integral with the transported inverse is not yet asserted.

Lean code for Proposition126 declarations
  • def LeanRidgelet.fourierDilationTransform (m : ) [NeZero m] (s t : ) :
      (LeanRidgelet.ParameterSpace m s t) ≃ₗᵢ[]
        (LeanRidgelet.BochnerL2 (LeanRidgelet.InputSpace m)
            (LeanRidgelet.FiberSpace m s t) MeasureTheory.volume)
    def LeanRidgelet.fourierDilationTransform
      (m : ) [NeZero m] (s t : ) :
      (LeanRidgelet.ParameterSpace m s
            t) ≃ₗᵢ[]
        (LeanRidgelet.BochnerL2
            (LeanRidgelet.InputSpace m)
            (LeanRidgelet.FiberSpace m s t)
            MeasureTheory.volume)
    Implementation after :=
    :=
      parameterCoordinateEquiv m s t
    The unitary coordinate transform `T` in the transported coordinate model. 
  • complete
    theorem LeanRidgelet.inverseFourierDilationTransform_apply_fourierDilationTransform
      (m : ) [NeZero m] (s t : )
      (γ : (LeanRidgelet.ParameterSpace m s t)) :
      (LeanRidgelet.inverseFourierDilationTransform m s t)
          ((LeanRidgelet.fourierDilationTransform m s t) γ) =
        γ
    theorem LeanRidgelet.inverseFourierDilationTransform_apply_fourierDilationTransform
      (m : ) [NeZero m] (s t : )
      (γ :
        (LeanRidgelet.ParameterSpace m s
            t)) :
      (LeanRidgelet.inverseFourierDilationTransform
            m s t)
          ((LeanRidgelet.fourierDilationTransform
              m s t)
            γ) =
        γ
  • def LeanRidgelet.fourierDilationCompatibilityDomain {m : } [NeZero m]
      (s t : ) : Set (SchwartzMap (LeanRidgelet.InputSpace m × ) )
    def LeanRidgelet.fourierDilationCompatibilityDomain
      {m : } [NeZero m] (s t : ) :
      Set
        (SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
    Implementation after :=
    :=
      {γ | AEStronglyMeasurable (fourierDilationTransformFiber s t γ) volume ∧
        Integrable (fun x : InputSpace m =>
          fiberSobolevNormSq s t (fourierDilationTransformFiberCore s t γ x))}
    The manuscript compatibility domain `S^T_{s,t}(Θ)` for Schwartz parameter data.
    
    The two clauses keep the analytic responsibilities visible: strong measurability of the
    completion-valued core and integrability of its Sobolev graph term.  This is a set predicate,
    not a structure carrying unproved analytic assumptions. 
  • complete
    theorem LeanRidgelet.mem_fourierDilationCompatibilityDomain_iff_memLp {m : }
      [NeZero m] (s t : )
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) ) :
      γ  LeanRidgelet.fourierDilationCompatibilityDomain s t 
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber s t γ) 2
          MeasureTheory.volume
    theorem LeanRidgelet.mem_fourierDilationCompatibilityDomain_iff_memLp
      {m : } [NeZero m] (s t : )
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) ) :
      γ 
          LeanRidgelet.fourierDilationCompatibilityDomain
            s t 
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber
            s t γ)
          2 MeasureTheory.volume
    Membership in the concrete compatibility domain is exactly Bochner `L²` membership of the
    Fourier--dilation core.  The base part is automatically integrable, so only measurability and the
    Sobolev graph term remain in the set definition. 
  • complete
    theorem LeanRidgelet.fourierDilationTransform_parameterSchwartzRealization_apply_ae
      {m : } [NeZero m] (s t : )
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber s t γ) 2
          MeasureTheory.volume) :
      ((LeanRidgelet.fourierDilationTransform m s t)
              (LeanRidgelet.parameterSchwartzRealization s t γ
                )) =ᵐ[MeasureTheory.volume]
        LeanRidgelet.fourierDilationTransformFiber s t γ
    theorem LeanRidgelet.fourierDilationTransform_parameterSchwartzRealization_apply_ae
      {m : } [NeZero m] (s t : )
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber
            s t γ)
          2 MeasureTheory.volume) :
      ((LeanRidgelet.fourierDilationTransform
                m s t)
              (LeanRidgelet.parameterSchwartzRealization
                s t γ
                )) =ᵐ[MeasureTheory.volume]
        LeanRidgelet.fourierDilationTransformFiber
          s t γ
  • def LeanRidgelet.inverseFourierDilationTransformCore {m : }
      (u : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      (p : LeanRidgelet.InputSpace m × ) : 
    def LeanRidgelet.inverseFourierDilationTransformCore
      {m : }
      (u :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      (p : LeanRidgelet.InputSpace m × ) : 
    Implementation after :=
    :=
      (2 * Real.pi : ℂ)⁻¹ *
        ∫ z : InputSpace m × ℝ, u z * inverseFourierDilationKernel p z
    The Fourier expression for the inverse coordinate transform on a Schwartz test function. 
Definition13
Statement uses 3
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used by 1L∃∀N

Let m\ge1, s,t\in\mathbb R, \sigma\in\mathcal A_{s,t}, and let T and L_\sigma be Definitions 11 and 8. Define S_\sigma:=\widetilde L_\sigma T:\mathcal G_{s,t}\to L^2(\mathbb R^m),\qquad S_\sigma[\gamma](x):=L_\sigma[T[\gamma](x,\cdot)].

Lean code for Definition135 declarations
  • complete
    def LeanRidgelet.networkSynthesis (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      (LeanRidgelet.ParameterSpace m s t) →L[]
        (LeanRidgelet.TargetSpace m)
    def LeanRidgelet.networkSynthesis (m : )
      [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      (LeanRidgelet.ParameterSpace m s
            t) →L[]
        (LeanRidgelet.TargetSpace m)
    Implementation after :=
    :=
      networkSynthesisMap m s t σ
    Synthesis associated with an activation coordinate in the transported `T`-coordinate model. 
  • complete
    theorem LeanRidgelet.networkSynthesis_eq_unitarySynthesis (m : ) [NeZero m]
      (s t : ) (σ : (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.networkSynthesis m s t σ =
        LeanRidgelet.unitarySynthesis MeasureTheory.volume
          (LeanRidgelet.parameterCoordinateEquiv m s t)
          (LeanRidgelet.activationFiberFunctional m s t σ)
    theorem LeanRidgelet.networkSynthesis_eq_unitarySynthesis
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.networkSynthesis m s t σ =
        LeanRidgelet.unitarySynthesis
          MeasureTheory.volume
          (LeanRidgelet.parameterCoordinateEquiv
            m s t)
          (LeanRidgelet.activationFiberFunctional
            m s t σ)
    The concrete synthesis is the specialization of the abstract unitary factorization to the
    transported coordinate model `T = I`. 
  • complete
    theorem LeanRidgelet.networkSynthesis_apply_fourierDilation_ae (m : )
      [NeZero m] (s t : ) (σ : (LeanRidgelet.ActivationSpace s t))
      (γ : (LeanRidgelet.ParameterSpace m s t)) :
      ((LeanRidgelet.networkSynthesis m s t σ) γ) =ᵐ[MeasureTheory.volume]
        fun x 
        (LeanRidgelet.activationFiberFunctional m s t σ)
          (((LeanRidgelet.fourierDilationTransform m s t) γ) x)
    theorem LeanRidgelet.networkSynthesis_apply_fourierDilation_ae
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (γ :
        (LeanRidgelet.ParameterSpace m s
            t)) :
      ((LeanRidgelet.networkSynthesis m s t
                σ)
              γ) =ᵐ[MeasureTheory.volume]
        fun x 
        (LeanRidgelet.activationFiberFunctional
            m s t σ)
          (((LeanRidgelet.fourierDilationTransform
                    m s t)
                  γ)
            x)
    Pointwise manuscript factorization `S[γ](x) = L_σ[T[γ](x, ·)]`.
    
    Although the transported coordinate model makes `T` definitionally the identity, this theorem
    keeps the unitary transform explicit and is therefore the interface used by the concrete Fourier
    construction. 
  • complete
    theorem LeanRidgelet.networkSynthesis_parameterSchwartzRealization_apply_ae
      {m : } [NeZero m] (s t : ) (σ : (LeanRidgelet.ActivationSpace s t))
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber s t γ) 2
          MeasureTheory.volume) :
      ((LeanRidgelet.networkSynthesis m s t σ)
              (LeanRidgelet.parameterSchwartzRealization s t γ
                )) =ᵐ[MeasureTheory.volume]
        fun x 
        (LeanRidgelet.activationFiberFunctional m s t σ)
          (LeanRidgelet.fourierDilationTransformFiber s t γ x)
    theorem LeanRidgelet.networkSynthesis_parameterSchwartzRealization_apply_ae
      {m : } [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber
            s t γ)
          2 MeasureTheory.volume) :
      ((LeanRidgelet.networkSynthesis m s t
                σ)
              (LeanRidgelet.parameterSchwartzRealization
                s t γ
                )) =ᵐ[MeasureTheory.volume]
        fun x 
        (LeanRidgelet.activationFiberFunctional
            m s t σ)
          (LeanRidgelet.fourierDilationTransformFiber
            s t γ x)
    On the Schwartz compatibility domain, synthesis is represented by the concrete
    Fourier--dilation core.  This is the Hilbert-space formula (29) before expanding the activation
    functional into its weighted Fourier pairing. 
  • complete
    theorem LeanRidgelet.networkSynthesis_parameterSchwartzRealization_fourierPairing_ae
      {m : } [NeZero m] (s t : ) (σ : (LeanRidgelet.ActivationSpace s t))
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber s t γ) 2
          MeasureTheory.volume) :
      ((LeanRidgelet.networkSynthesis m s t σ)
              (LeanRidgelet.parameterSchwartzRealization s t γ
                )) =ᵐ[MeasureTheory.volume]
        fun x 
        (2 * Real.pi) ^ (m - 1) *
          inner  (star σ)
            (LeanRidgelet.fiberDualCoordinateCoreValue s t
              (LeanRidgelet.fourierDilationTransformFiberCore s t γ x))
    theorem LeanRidgelet.networkSynthesis_parameterSchwartzRealization_fourierPairing_ae
      {m : } [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber
            s t γ)
          2 MeasureTheory.volume) :
      ((LeanRidgelet.networkSynthesis m s t
                σ)
              (LeanRidgelet.parameterSchwartzRealization
                s t γ
                )) =ᵐ[MeasureTheory.volume]
        fun x 
        (2 * Real.pi) ^ (m - 1) *
          inner  (star σ)
            (LeanRidgelet.fiberDualCoordinateCoreValue
              s t
              (LeanRidgelet.fourierDilationTransformFiberCore
                s t γ x))
    Weighted-Fourier pairing form of synthesis on the Schwartz compatibility domain. 
Theorem14
uses 1used by 1L∃∀N

Let m\ge1, s,t\in\mathbb R, \sigma\in\mathcal A_{s,t}, and \gamma\in\mathcal G_{s,t}. Then \|S[\gamma]\|_2\le (2\pi)^{m-1}\|\sigma\|_{\mathcal A_{s,t}}\|\gamma\|_{\mathcal G_{s,t}}. In addition, if \gamma lies in the Schwartz compatibility domain, the classical integral is absolutely defined, and the realized activation acts by integration against a function \sigma_{\mathrm{cl}}, then S_\sigma[\gamma](x)=\int\gamma(a,b)\sigma_{\mathrm{cl}}(a\cdot x-b)\,da\,db \quad\text{for a.e. }x.

Lean code for Theorem144 declarations
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    complete
    theorem LeanRidgelet.l2_theorem_one_bounded_synthesis (m : ) [NeZero m]
      (s t : ) (σ : (LeanRidgelet.ActivationSpace s t))
      (γ : (LeanRidgelet.ParameterSpace m s t)) :
      (((LeanRidgelet.networkSynthesis m s t σ)
                γ) =ᵐ[MeasureTheory.volume]
          fun x 
          (LeanRidgelet.activationFiberFunctional m s t σ) (γ x)) 
        (LeanRidgelet.networkSynthesis m s t σ) γ 
          (2 * Real.pi) ^ (m - 1) * σ * γ
    theorem LeanRidgelet.l2_theorem_one_bounded_synthesis
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (γ :
        (LeanRidgelet.ParameterSpace m s
            t)) :
      (((LeanRidgelet.networkSynthesis m s t
                  σ)
                γ) =ᵐ[MeasureTheory.volume]
          fun x 
          (LeanRidgelet.activationFiberFunctional
              m s t σ)
            (γ x)) 
        (LeanRidgelet.networkSynthesis m s t
                σ)
              γ 
          (2 * Real.pi) ^ (m - 1) * σ * γ
    Manuscript Theorem 14: coordinate synthesis is pointwise
    evaluation and satisfies the concrete bound. 
  • complete
    theorem LeanRidgelet.norm_networkSynthesis_le (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.networkSynthesis m s t σ 
        (2 * Real.pi) ^ (m - 1) * σ
    theorem LeanRidgelet.norm_networkSynthesis_le
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.networkSynthesis m s t
            σ 
        (2 * Real.pi) ^ (m - 1) * σ
    The concrete operator-norm estimate for synthesis. 
  • def LeanRidgelet.classicalSynthesisIntegral {m : }
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) ) (σcl :   )
      (x : LeanRidgelet.InputSpace m) : 
    def LeanRidgelet.classicalSynthesisIntegral
      {m : }
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      (σcl :   )
      (x : LeanRidgelet.InputSpace m) : 
    Implementation after :=
    :=
      ∫ p : InputSpace m × ℝ, γ p * σcl (inner ℝ p.1 x - p.2)
    The classical network synthesis integral `x ↦ ∫ γ(a,b) σcl(⟨a,x⟩-b) da db`. 
  • theorem LeanRidgelet.networkSynthesis_parameterSchwartzRealization_classical_ae
      {m : } [NeZero m] (s t : ) (σ : (LeanRidgelet.ActivationSpace s t))
      {σcl :   }
      (hσcl :
         (φ : SchwartzMap  ),
          ((LeanRidgelet.activationRealization s t) σ) φ =
             (z : ), φ z * σcl z)
      (γ : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber s t γ) 2
          MeasureTheory.volume)
      (hint :
         (x : LeanRidgelet.InputSpace m),
          MeasureTheory.Integrable (fun p  γ p * σcl (inner  p.1 x - p.2))
            MeasureTheory.volume) :
      ((LeanRidgelet.networkSynthesis m s t σ)
              (LeanRidgelet.parameterSchwartzRealization s t γ
                )) =ᵐ[MeasureTheory.volume]
        LeanRidgelet.classicalSynthesisIntegral γ σcl
    theorem LeanRidgelet.networkSynthesis_parameterSchwartzRealization_classical_ae
      {m : } [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      {σcl :   }
      (hσcl :
         (φ : SchwartzMap  ),
          ((LeanRidgelet.activationRealization
                  s t)
                σ)
              φ =
             (z : ), φ z * σcl z)
      (γ :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      ( :
        MeasureTheory.MemLp
          (LeanRidgelet.fourierDilationTransformFiber
            s t γ)
          2 MeasureTheory.volume)
      (hint :
         (x : LeanRidgelet.InputSpace m),
          MeasureTheory.Integrable
            (fun p 
              γ p * σcl (inner  p.1 x - p.2))
            MeasureTheory.volume) :
      ((LeanRidgelet.networkSynthesis m s t
                σ)
              (LeanRidgelet.parameterSchwartzRealization
                s t γ
                )) =ᵐ[MeasureTheory.volume]
        LeanRidgelet.classicalSynthesisIntegral
          γ σcl
    **Agreement with the classical synthesis integral** (manuscript Theorem 14, `thm:bdd.S`,
    classical part).  Let `σ` be an activation coordinate whose realized classical activation
    `σ = 𝓕⁻¹_paper[σ♯]` acts on test functions by integration against `σcl`, and let `γ` be a
    Schwartz parameter distribution in the compatibility domain.  If the classical integral is
    defined at every input, then the Hilbert-space synthesis operator is represented almost
    everywhere by the classical network integral `∫ γ(a,b) σcl(⟨a,x⟩-b) da db`.
    

Section 4: Neural-Network Specialization: Ridgelet Reconstruction from the Fourier Expression

Definition15
uses 1
Used by 2
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L∃∀N

Let m\ge1, s,t\in\mathbb R, h\in\mathcal H_{s,t}, and f\in L^2(\mathbb R^m). Define R_h[f]:=T^*[f\otimes h],\qquad \rho_h^\sharp:=|\omega|^m\overline h, \qquad \rho_h:=\mathcal F^{-1}[\rho_h^\sharp]. The spectrum identity holds pointwise on the Schwartz core and distributionally on the completion. For Schwartz h, the distribution \rho_h is represented by a function, and its classical ridgelet transform is R[f;\rho_h](a,b):=\int f(x)\overline{\rho_h(a\cdot x-b)}\,dx.

Lean code for Definition1510 declarations
  • complete
    def LeanRidgelet.ridgeletOperator (m : ) [NeZero m] (s t : )
      (h : LeanRidgelet.FiberSpace m s t) :
      (LeanRidgelet.TargetSpace m) →L[]
        (LeanRidgelet.ParameterSpace m s t)
    def LeanRidgelet.ridgeletOperator (m : )
      [NeZero m] (s t : )
      (h : LeanRidgelet.FiberSpace m s t) :
      (LeanRidgelet.TargetSpace m) →L[]
        (LeanRidgelet.ParameterSpace m s t)
    Implementation after :=
    :=
      fiberRidgelet volume h
    The simple-tensor operator `J_h` in the transported unitary-coordinate model.
    
    The name `ridgeletOperator` is retained for API compatibility; on the original parameter space
    the corresponding operator is `R_h = T* J_h`. 
  • complete
    theorem LeanRidgelet.ridgeletOperator_eq_unitaryRidgelet (m : ) [NeZero m]
      (s t : ) (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.ridgeletOperator m s t h =
        LeanRidgelet.unitaryRidgelet MeasureTheory.volume
          (LeanRidgelet.parameterCoordinateEquiv m s t) h
    theorem LeanRidgelet.ridgeletOperator_eq_unitaryRidgelet
      (m : ) [NeZero m] (s t : )
      (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.ridgeletOperator m s t h =
        LeanRidgelet.unitaryRidgelet
          MeasureTheory.volume
          (LeanRidgelet.parameterCoordinateEquiv
            m s t)
          h
    The concrete ridgelet operator is the abstract `R_h = T* J_h` specialized to the transported
    coordinate model `T = I`. 
  • complete
    def LeanRidgelet.fiberBaseCoordinate (m : ) [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L[]
        (LeanRidgelet.L2  MeasureTheory.volume)
    def LeanRidgelet.fiberBaseCoordinate (m : )
      [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L[]
        (LeanRidgelet.L2 
            MeasureTheory.volume)
    Implementation after :=
    :=
      (fiberBaseCoordinateCoreL m s t).extend
        (UniformSpace.Completion.toComplL : FiberCore m s t →L[ℂ] FiberSpace m s t)
    The square-root weighted coordinate, extended to the completed fiber Hilbert space. 
  • def LeanRidgelet.ridgeletSpectrum (m : ) [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L⋆[] TemperedDistribution  
    def LeanRidgelet.ridgeletSpectrum (m : )
      [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L⋆[]
        TemperedDistribution  
    Implementation after :=
    := ContinuousLinearMap.toPointwiseConvergenceCLM ℂ (RingHom.id ℂ)
        (SchwartzMap ℝ ℂ) ℂ
          ((innerSL ℂ (fiberBaseCoordinate m s t h)).comp
            (fiberBaseCoordinateSchwartz m))
      map_add' h r := by
        ext φ
        change inner ℂ
            (fiberBaseCoordinate m s t (h + r))
            (fiberBaseCoordinateSchwartz m φ) =
          inner ℂ (fiberBaseCoordinate m s t h) (fiberBaseCoordinateSchwartz m φ) +
            inner ℂ (fiberBaseCoordinate m s t r) (fiberBaseCoordinateSchwartz m φ)
        rw [map_add, inner_add_left]
      map_smul' c h := by
        ext φ
        simp
      cont := by
        apply PointwiseConvergenceCLM.continuous_of_continuous_eval
        intro φ
        exact (innerSLFlip ℂ (fiberBaseCoordinateSchwartz m φ)).continuous.comp
          (fiberBaseCoordinate m s t).continuous
    The manuscript spectrum `ρ♯ = |ω|ᵐ conj h` for a completed coefficient vector.
    
    The formula is realized through the `L²` pairing of square-root weighted coordinates.  This avoids
    the invalid intermediate operation of multiplying an arbitrary tempered distribution by the
    nonsmooth function `|ω|ᵐ` in odd dimensions.  The dependence on `h` is conjugate-linear, as in the
    manuscript formula. 
  • complete
    theorem LeanRidgelet.ridgeletSpectrum_coe (m : ) [NeZero m] (s t : )
      (h : LeanRidgelet.FiberCore m s t) :
      (LeanRidgelet.ridgeletSpectrum m s t) h =
        LeanRidgelet.ridgeletSpectrumCore m h.toSchwartz
    theorem LeanRidgelet.ridgeletSpectrum_coe (m : )
      [NeZero m] (s t : )
      (h : LeanRidgelet.FiberCore m s t) :
      (LeanRidgelet.ridgeletSpectrum m s t)
          h =
        LeanRidgelet.ridgeletSpectrumCore m
          h.toSchwartz
    The completed spectrum agrees with the pointwise `|ω|ᵐ conj h` formula on the dense Schwartz
    core. 
  • def LeanRidgelet.ridgeletFunction (m : ) [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L⋆[] TemperedDistribution  
    def LeanRidgelet.ridgeletFunction (m : )
      [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L⋆[]
        TemperedDistribution  
    Implementation after :=
    := paperFourierInvDistribution (ridgeletSpectrum m s t h)
      map_add' h r := by simp
      map_smul' c h := by simp
      cont := paperFourierInvDistribution.continuous.comp (ridgeletSpectrum m s t).continuous
    Reconstruct the ridgelet function `ρ` from a completed coefficient vector `h` by applying the
    manuscript inverse Fourier transform to `ρ♯`. 
  • complete
    theorem LeanRidgelet.paperFourierDistribution_ridgeletFunction (m : )
      [NeZero m] (s t : ) (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.Fourier.paperFourierDistribution
          ((LeanRidgelet.ridgeletFunction m s t) h) =
        (LeanRidgelet.ridgeletSpectrum m s t) h
    theorem LeanRidgelet.paperFourierDistribution_ridgeletFunction
      (m : ) [NeZero m] (s t : )
      (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.Fourier.paperFourierDistribution
          ((LeanRidgelet.ridgeletFunction m s
              t)
            h) =
        (LeanRidgelet.ridgeletSpectrum m s t)
          h
    The reconstructed completed ridgelet function has spectrum `ρ♯`. 
  • def LeanRidgelet.classicalRidgeletFunction (m : ) (h : SchwartzMap  )
      (z : ) : 
    def LeanRidgelet.classicalRidgeletFunction
      (m : ) (h : SchwartzMap  ) (z : ) :
      
    Implementation after :=
    :=
      (2 * Real.pi : ℂ)⁻¹ *
        ∫ ω : ℝ, ridgeletSpectrumCoreFn m h ω * Complex.exp (Complex.I * (z * ω))
    The classical ridgelet function `ρ = 𝓕⁻¹_paper[ρ♯]` of a Schwartz coefficient vector,
    with manuscript spectrum `ρ♯(ω) = |ω|^m conj h(ω)`. 
  • def LeanRidgelet.classicalRidgeletIntegral {m : }
      (f : LeanRidgelet.InputSpace m  ) (ρ :   )
      (p : LeanRidgelet.InputSpace m × ) : 
    def LeanRidgelet.classicalRidgeletIntegral
      {m : }
      (f : LeanRidgelet.InputSpace m  )
      (ρ :   )
      (p : LeanRidgelet.InputSpace m × ) : 
    Implementation after :=
    :=
      ∫ x : InputSpace m, f x * conj (ρ (inner ℝ p.1 x - p.2))
    The classical ridgelet transform `R[f;ρ](a,b) = ∫ f(x) conj(ρ(⟨a,x⟩-b)) dx`. 
  • theorem LeanRidgelet.ridgeletFunctionCore_apply_classical (m : )
      (h φ : SchwartzMap  ) :
      (LeanRidgelet.ridgeletFunctionCore m h) φ =
         (z : ), φ z * LeanRidgelet.classicalRidgeletFunction m h z
    theorem LeanRidgelet.ridgeletFunctionCore_apply_classical
      (m : ) (h φ : SchwartzMap  ) :
      (LeanRidgelet.ridgeletFunctionCore m h)
          φ =
         (z : ),
          φ z *
            LeanRidgelet.classicalRidgeletFunction
              m h z
    The repository ridgelet distribution `ρ = 𝓕⁻¹_paper[ρ♯]` acts on test functions by
    integration against the classical ridgelet function.  This identifies
    `classicalRidgeletFunction` as the pointwise realization of `ridgeletFunctionCore`. 
Lemma16
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L∃∀N

Let m\ge1, s,t\in\mathbb R, h\in\mathcal H_{s,t}, and f\in L^2(\mathbb R^m). Then T[R_h[f]](x)=f(x)h\quad\text{for a.e. }x. If f and h are Schwartz and the classical ridgelet integral of Definition 15 is integrable, then for every (a,b) it equals \frac1{2\pi}\int f(x)h(\omega)e^{-i\omega(a\cdot x-b)}|\omega|^m\,dx\,d\omega. The separate bias/input Fourier formulas (32)--(33) are not asserted here.

Lean code for Lemma164 theorems
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    complete
    theorem LeanRidgelet.l2_lemma_one_ridgelet_fiber_representation (m : )
      [NeZero m] (s t : ) (h : LeanRidgelet.FiberSpace m s t)
      (f : (LeanRidgelet.TargetSpace m)) :
      ((LeanRidgelet.ridgeletOperator m s t h) f) =ᵐ[MeasureTheory.volume]
        fun x  f x  h
    theorem LeanRidgelet.l2_lemma_one_ridgelet_fiber_representation
      (m : ) [NeZero m] (s t : )
      (h : LeanRidgelet.FiberSpace m s t)
      (f : (LeanRidgelet.TargetSpace m)) :
      ((LeanRidgelet.ridgeletOperator m s t
                h)
              f) =ᵐ[MeasureTheory.volume]
        fun x  f x  h
    Manuscript Lemma 16: the formalized coordinate representation is a
    simple tensor. 
  • complete
    theorem LeanRidgelet.fourierDilationTransform_ridgeletOperator_apply_ae (m : )
      [NeZero m] (s t : ) (h : LeanRidgelet.FiberSpace m s t)
      (f : (LeanRidgelet.TargetSpace m)) :
      ((LeanRidgelet.fourierDilationTransform m s t)
              ((LeanRidgelet.ridgeletOperator m s t h)
                f)) =ᵐ[MeasureTheory.volume]
        fun x  f x  h
    theorem LeanRidgelet.fourierDilationTransform_ridgeletOperator_apply_ae
      (m : ) [NeZero m] (s t : )
      (h : LeanRidgelet.FiberSpace m s t)
      (f : (LeanRidgelet.TargetSpace m)) :
      ((LeanRidgelet.fourierDilationTransform
                m s t)
              ((LeanRidgelet.ridgeletOperator
                  m s t h)
                f)) =ᵐ[MeasureTheory.volume]
        fun x  f x  h
    The concrete form of `T[R_h[f]] = f ⊗ h`, corresponding to equation (34). 
  • theorem LeanRidgelet.classicalRidgeletIntegral_eq_inverseTensorIntegral {m : }
      (f : SchwartzMap (LeanRidgelet.InputSpace m) ) (h : SchwartzMap  )
      (p : LeanRidgelet.InputSpace m × ) :
      LeanRidgelet.classicalRidgeletIntegral (⇑f)
          (LeanRidgelet.classicalRidgeletFunction m h) p =
        (2 * Real.pi)⁻¹ *
           (z : LeanRidgelet.InputSpace m × ),
            f z.1 * h z.2 * LeanRidgelet.inverseFourierDilationKernel p z
    theorem LeanRidgelet.classicalRidgeletIntegral_eq_inverseTensorIntegral
      {m : }
      (f :
        SchwartzMap
          (LeanRidgelet.InputSpace m) )
      (h : SchwartzMap  )
      (p : LeanRidgelet.InputSpace m × ) :
      LeanRidgelet.classicalRidgeletIntegral
          (⇑f)
          (LeanRidgelet.classicalRidgeletFunction
            m h)
          p =
        (2 * Real.pi)⁻¹ *
           (z :
            LeanRidgelet.InputSpace m × ),
            f z.1 * h z.2 *
              LeanRidgelet.inverseFourierDilationKernel
                p z
    **Agreement with the classical ridgelet integral** (manuscript Definition of `R[f;ρ]` and
    Lemma `lem:fourier`, classical part).  For a Schwartz function `f` and a Schwartz coefficient
    vector `h`, the classical ridgelet transform with respect to the classical ridgelet function of
    spectrum `|ω|^m conj h` equals, at every parameter point, the inverse-coordinate integral
    formula (13) applied to the tensor section `(x,ω) ↦ f(x) h(ω)` — the coordinate representative
    of `T[R_h[f]]`.
    
  • theorem LeanRidgelet.classicalRidgeletIntegral_eq_inverseFourierDilationTransformCore
      {m : } (f : SchwartzMap (LeanRidgelet.InputSpace m) )
      (h : SchwartzMap  )
      (u : SchwartzMap (LeanRidgelet.InputSpace m × ) )
      (hu :  (z : LeanRidgelet.InputSpace m × ), u z = f z.1 * h z.2)
      (p : LeanRidgelet.InputSpace m × ) :
      LeanRidgelet.classicalRidgeletIntegral (⇑f)
          (LeanRidgelet.classicalRidgeletFunction m h) p =
        LeanRidgelet.inverseFourierDilationTransformCore u p
    theorem LeanRidgelet.classicalRidgeletIntegral_eq_inverseFourierDilationTransformCore
      {m : }
      (f :
        SchwartzMap
          (LeanRidgelet.InputSpace m) )
      (h : SchwartzMap  )
      (u :
        SchwartzMap
          (LeanRidgelet.InputSpace m × ) )
      (hu :
         (z : LeanRidgelet.InputSpace m × ),
          u z = f z.1 * h z.2)
      (p : LeanRidgelet.InputSpace m × ) :
      LeanRidgelet.classicalRidgeletIntegral
          (⇑f)
          (LeanRidgelet.classicalRidgeletFunction
            m h)
          p =
        LeanRidgelet.inverseFourierDilationTransformCore
          u p
    The classical ridgelet integral agrees with the inverse coordinate-transform formula (13)
    on any Schwartz representative of the tensor section `(x,ω) ↦ f(x) h(ω)`. 
Theorem17
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used by 0L∃∀N

Let m\ge1, s,t\in\mathbb R, \sigma\in\mathcal A_{s,t}, and h\in\mathcal H_{s,t}. Then S_\sigma\circ R_h=L_\sigma[h]I, that is, S_\sigma[R_h[f]]=L_\sigma[h]f for every f\in L^2(\mathbb R^m). If a classical ridgelet function \rho has h=|\omega|^{-m}\overline{\rho^\sharp}, this becomes S_\sigma[R[f;\rho]]=\langle\!\langle\sigma,\rho\rangle\!\rangle f; bundling the forward map \rho\mapsto h remains outside the current statement.

Lean code for Theorem172 theorems
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    complete
    theorem LeanRidgelet.l2_theorem_two_reconstruction (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t))
      (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.networkSynthesis m s t σ ∘SL
          LeanRidgelet.ridgeletOperator m s t h =
        (LeanRidgelet.activationFiberFunctional m s t σ) h 
          ContinuousLinearMap.id  (LeanRidgelet.TargetSpace m)
    theorem LeanRidgelet.l2_theorem_two_reconstruction
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.networkSynthesis m s t
            σ ∘SL
          LeanRidgelet.ridgeletOperator m s t
            h =
        (LeanRidgelet.activationFiberFunctional
              m s t σ)
            h 
          ContinuousLinearMap.id 
            (LeanRidgelet.TargetSpace m)
    Manuscript Theorem 17: synthesis after a prescribed
    coefficient is scalar reconstruction. 
  • complete
    theorem LeanRidgelet.networkSynthesis_comp_ridgeletOperator (m : ) [NeZero m]
      (s t : ) (σ : (LeanRidgelet.ActivationSpace s t))
      (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.networkSynthesis m s t σ ∘SL
          LeanRidgelet.ridgeletOperator m s t h =
        (LeanRidgelet.activationFiberFunctional m s t σ) h 
          ContinuousLinearMap.id  (LeanRidgelet.TargetSpace m)
    theorem LeanRidgelet.networkSynthesis_comp_ridgeletOperator
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.networkSynthesis m s t
            σ ∘SL
          LeanRidgelet.ridgeletOperator m s t
            h =
        (LeanRidgelet.activationFiberFunctional
              m s t σ)
            h 
          ContinuousLinearMap.id 
            (LeanRidgelet.TargetSpace m)
    Coordinate reconstruction `\widetilde L_σ J_h = L_σ[h] I`. 

Section 5: Neural-Network Specialization: Adjoint, Null Space, and Complete General Solution

Definition18
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used by 1L∃∀N

Let m\ge1, s,t\in\mathbb R, and \sigma\in\mathcal A_{s,t}. Define the Riesz vector h_\sigma\in\mathcal H_{s,t} and normalization c_\sigma by L_\sigma[h]=\langle h,h_\sigma\rangle,\qquad c_\sigma:=\|h_\sigma\|^2=\|L_\sigma\|^2. Define the adjoint ridgelet distribution \sigma_*:=\rho_{h_\sigma}; equivalently, \sigma_*^\sharp=|\omega|^m\overline{h_\sigma}.

Lean code for Definition184 declarations
  • complete
    def LeanRidgelet.activationRieszRepresenter (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.FiberSpace m s t
    def LeanRidgelet.activationRieszRepresenter
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.FiberSpace m s t
    Implementation after :=
    :=
      rieszRepresenter (activationFiberFunctional m s t σ)
    The Riesz representer `h_σ` associated with an activation functional. 
  • complete
    def LeanRidgelet.activationNormalization (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) : 
    def LeanRidgelet.activationNormalization
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      
    Implementation after :=
    :=
      fiberNormalization (activationFiberFunctional m s t σ)
    The normalization constant `cσ = ‖hσ‖²`. 
  • def LeanRidgelet.ridgeletFunction (m : ) [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L⋆[] TemperedDistribution  
    def LeanRidgelet.ridgeletFunction (m : )
      [NeZero m] (s t : ) :
      LeanRidgelet.FiberSpace m s t →L⋆[]
        TemperedDistribution  
    Implementation after :=
    := paperFourierInvDistribution (ridgeletSpectrum m s t h)
      map_add' h r := by simp
      map_smul' c h := by simp
      cont := paperFourierInvDistribution.continuous.comp (ridgeletSpectrum m s t).continuous
    Reconstruct the ridgelet function `ρ` from a completed coefficient vector `h` by applying the
    manuscript inverse Fourier transform to `ρ♯`. 
  • complete
    theorem LeanRidgelet.paperFourierDistribution_ridgeletFunction (m : )
      [NeZero m] (s t : ) (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.Fourier.paperFourierDistribution
          ((LeanRidgelet.ridgeletFunction m s t) h) =
        (LeanRidgelet.ridgeletSpectrum m s t) h
    theorem LeanRidgelet.paperFourierDistribution_ridgeletFunction
      (m : ) [NeZero m] (s t : )
      (h : LeanRidgelet.FiberSpace m s t) :
      LeanRidgelet.Fourier.paperFourierDistribution
          ((LeanRidgelet.ridgeletFunction m s
              t)
            h) =
        (LeanRidgelet.ridgeletSpectrum m s t)
          h
    The reconstructed completed ridgelet function has spectrum `ρ♯`. 
Lemma19
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Under Definition 18, for every f\in L^2(\mathbb R^m), S_\sigma^*=R_{h_\sigma},\qquad S_\sigma S_\sigma^*=c_\sigma I,\qquad \|S_\sigma^*[f]\|^2=c_\sigma\|f\|^2. With \sigma_* from Definition 18, the first identity is equivalently S_\sigma^*[f]=R[f;\sigma_*].

Lean code for Lemma193 theorems
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    complete
    theorem LeanRidgelet.l2_lemma_two_adjoint (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      ContinuousLinearMap.adjoint (LeanRidgelet.networkSynthesis m s t σ) =
          LeanRidgelet.ridgeletOperator m s t
            (LeanRidgelet.activationRieszRepresenter m s t σ) 
        LeanRidgelet.networkSynthesis m s t σ ∘SL
            ContinuousLinearMap.adjoint
              (LeanRidgelet.networkSynthesis m s t σ) =
          (LeanRidgelet.activationNormalization m s t σ) 
            ContinuousLinearMap.id  (LeanRidgelet.TargetSpace m)
    theorem LeanRidgelet.l2_lemma_two_adjoint (m : )
      [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      ContinuousLinearMap.adjoint
            (LeanRidgelet.networkSynthesis m s
              t σ) =
          LeanRidgelet.ridgeletOperator m s t
            (LeanRidgelet.activationRieszRepresenter
              m s t σ) 
        LeanRidgelet.networkSynthesis m s t
              σ ∘SL
            ContinuousLinearMap.adjoint
              (LeanRidgelet.networkSynthesis m
                s t σ) =
          (LeanRidgelet.activationNormalization
                m s t σ) 
            ContinuousLinearMap.id 
              (LeanRidgelet.TargetSpace m)
    Manuscript Lemma 19: the adjoint uses the Riesz representer and
    satisfies the scaled coisometry identity. 
  • complete
    theorem LeanRidgelet.adjoint_networkSynthesis (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      ContinuousLinearMap.adjoint (LeanRidgelet.networkSynthesis m s t σ) =
        LeanRidgelet.ridgeletOperator m s t
          (LeanRidgelet.activationRieszRepresenter m s t σ)
    theorem LeanRidgelet.adjoint_networkSynthesis
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      ContinuousLinearMap.adjoint
          (LeanRidgelet.networkSynthesis m s t
            σ) =
        LeanRidgelet.ridgeletOperator m s t
          (LeanRidgelet.activationRieszRepresenter
            m s t σ)
    The adjoint synthesis operator is represented in coordinates by `J_{h_σ}`. 
  • complete
    theorem LeanRidgelet.networkSynthesis_comp_adjoint (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.networkSynthesis m s t σ ∘SL
          ContinuousLinearMap.adjoint
            (LeanRidgelet.networkSynthesis m s t σ) =
        (LeanRidgelet.activationNormalization m s t σ) 
          ContinuousLinearMap.id  (LeanRidgelet.TargetSpace m)
    theorem LeanRidgelet.networkSynthesis_comp_adjoint
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      LeanRidgelet.networkSynthesis m s t
            σ ∘SL
          ContinuousLinearMap.adjoint
            (LeanRidgelet.networkSynthesis m s
              t σ) =
        (LeanRidgelet.activationNormalization
              m s t σ) 
          ContinuousLinearMap.id 
            (LeanRidgelet.TargetSpace m)
    Synthesis composed with its adjoint is multiplication by `cσ`. 
Definition20
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L∃∀N

Let \sigma\in\mathcal A_{s,t} satisfy \sigma\ne0. Define S_\sigma^\dagger:=c_\sigma^{-1}S_\sigma^*,\qquad P_\sigma:=S_\sigma^\dagger S_\sigma. Then S_\sigma S_\sigma^\dagger=I and P_\sigma^*=P_\sigma.

Lean code for Definition204 declarations
  • complete
    def LeanRidgelet.normalizedNetworkRightInverse (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      (LeanRidgelet.TargetSpace m) →L[]
        (LeanRidgelet.ParameterSpace m s t)
    def LeanRidgelet.normalizedNetworkRightInverse
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      (LeanRidgelet.TargetSpace m) →L[]
        (LeanRidgelet.ParameterSpace m s t)
    Implementation after :=
    :=
      normalizedRightInverse volume (activationFiberFunctional m s t σ)
    The normalized Hilbert adjoint `c_σ⁻¹ S*`, giving the Moore--Penrose right inverse. 
  • complete
    def LeanRidgelet.networkVisibleProjection (m : ) [NeZero m] (s t : )
      (σ : (LeanRidgelet.ActivationSpace s t)) :
      (LeanRidgelet.ParameterSpace m s t) →L[]
        (LeanRidgelet.ParameterSpace m s t)
    def LeanRidgelet.networkVisibleProjection
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      (LeanRidgelet.ParameterSpace m s
            t) →L[]
        (LeanRidgelet.ParameterSpace m s t)
    Implementation after :=
    :=
      visibleProjection volume (activationFiberFunctional m s t σ)
    The canonical orthogonal parameter projection `P = S^\dagger S`.
    
    The name `networkVisibleProjection` is retained for API compatibility. 
  • complete
    theorem LeanRidgelet.normalizedNetworkRightInverse_rightInverse (m : )
      [NeZero m] (s t : ) {σ : (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0) :
      Function.RightInverse
        (LeanRidgelet.normalizedNetworkRightInverse m s t σ)
        (LeanRidgelet.networkSynthesis m s t σ)
    theorem LeanRidgelet.normalizedNetworkRightInverse_rightInverse
      (m : ) [NeZero m] (s t : )
      {σ :
        (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0) :
      Function.RightInverse
        (LeanRidgelet.normalizedNetworkRightInverse
            m s t σ)
        (LeanRidgelet.networkSynthesis m s t
            σ)
  • complete
    theorem LeanRidgelet.isSelfAdjoint_networkVisibleProjection (m : ) [NeZero m]
      (s t : ) (σ : (LeanRidgelet.ActivationSpace s t)) :
      IsSelfAdjoint (LeanRidgelet.networkVisibleProjection m s t σ)
    theorem LeanRidgelet.isSelfAdjoint_networkVisibleProjection
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t)) :
      IsSelfAdjoint
        (LeanRidgelet.networkVisibleProjection
          m s t σ)
Theorem21
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L∃∀N

Let \sigma\in\mathcal A_{s,t} satisfy \sigma\ne0, let (e_i)_{i\in I} be a Hilbert basis of L^2(\mathbb R^m), and let \gamma\in\mathcal G_{s,t}. Then \gamma\in\ker S_\sigma\iff L_\sigma[T[\gamma](x,\cdot)]=0\ \text{for a.e. }x \iff(\forall i)\;h_i[\gamma]\in\ker L_\sigma, and \gamma=\sum_iR_{h_i[\gamma]}[e_i] with unique coefficient vectors. For f\in L^2(\mathbb R^m), all solutions are exactly \{\gamma:S_\sigma[\gamma]=f\}=S_\sigma^\dagger[f]+\ker S_\sigma, and S_\sigma^\dagger[f] is the unique minimum-norm solution. A Hilbert basis of \ker L_\sigma further gives the double \ell^2 null expansion of Theorem 4.

Lean code for Theorem216 theorems
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    complete
    theorem LeanRidgelet.l2_theorem_three_null_space_and_general_solution.{u_1}
      {ι : Type u_1} (m : ) [NeZero m] (s t : )
      (b : HilbertBasis ι  (LeanRidgelet.TargetSpace m))
      {σ : (LeanRidgelet.ActivationSpace s t)} ( : σ  0)
      (f : (LeanRidgelet.TargetSpace m))
      (γ : (LeanRidgelet.ParameterSpace m s t)) :
      (γ  (↑(LeanRidgelet.networkSynthesis m s t σ)).ker 
          ∀ᵐ (x : LeanRidgelet.InputSpace m),
            (LeanRidgelet.activationFiberFunctional m s t σ) (γ x) = 0) 
        HasSum
            (fun i 
              (LeanRidgelet.ridgeletOperator m s t
                  (LeanRidgelet.fiberCoefficient MeasureTheory.volume (b i)
                    γ))
                (b i))
            γ 
          (γ  (↑(LeanRidgelet.networkSynthesis m s t σ)).ker 
               (i : ι),
                (LeanRidgelet.activationFiberFunctional m s t σ)
                    (LeanRidgelet.fiberCoefficient MeasureTheory.volume
                      (b i) γ) =
                  0) 
            (∀ (h : ι  LeanRidgelet.FiberSpace m s t),
                HasSum
                    (fun i 
                      (LeanRidgelet.ridgeletOperator m s t (h i)) (b i))
                    γ 
                   (i : ι),
                    h i =
                      LeanRidgelet.fiberCoefficient MeasureTheory.volume
                        (b i) γ) 
              ((LeanRidgelet.networkSynthesis m s t σ) γ = f 
                  γ -
                      (LeanRidgelet.normalizedNetworkRightInverse m s t σ)
                        f 
                    (↑(LeanRidgelet.networkSynthesis m s t σ)).ker) 
                 (δ : (LeanRidgelet.ParameterSpace m s t)),
                  (LeanRidgelet.networkSynthesis m s t σ) δ = f 
                    (LeanRidgelet.normalizedNetworkRightInverse m s t σ)
                            f 
                        δ 
                      ((LeanRidgelet.normalizedNetworkRightInverse m s t σ)
                              f =
                          δ 
                        (LeanRidgelet.normalizedNetworkRightInverse m s t σ)
                            f =
                          δ)
    theorem LeanRidgelet.l2_theorem_three_null_space_and_general_solution.{u_1}
      {ι : Type u_1} (m : ) [NeZero m]
      (s t : )
      (b :
        HilbertBasis ι 
          (LeanRidgelet.TargetSpace m))
      {σ :
        (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0)
      (f : (LeanRidgelet.TargetSpace m))
      (γ :
        (LeanRidgelet.ParameterSpace m s
            t)) :
      (γ 
            (↑(LeanRidgelet.networkSynthesis m
                  s t σ)).ker 
          ∀ᵐ (x : LeanRidgelet.InputSpace m),
            (LeanRidgelet.activationFiberFunctional
                  m s t σ)
                (γ x) =
              0) 
        HasSum
            (fun i 
              (LeanRidgelet.ridgeletOperator m
                  s t
                  (LeanRidgelet.fiberCoefficient
                    MeasureTheory.volume (b i)
                    γ))
                (b i))
            γ 
          (γ 
                (↑(LeanRidgelet.networkSynthesis
                      m s t σ)).ker 
               (i : ι),
                (LeanRidgelet.activationFiberFunctional
                      m s t σ)
                    (LeanRidgelet.fiberCoefficient
                      MeasureTheory.volume
                      (b i) γ) =
                  0) 
            (∀
                (h :
                  ι 
                    LeanRidgelet.FiberSpace m
                      s t),
                HasSum
                    (fun i 
                      (LeanRidgelet.ridgeletOperator
                          m s t (h i))
                        (b i))
                    γ 
                   (i : ι),
                    h i =
                      LeanRidgelet.fiberCoefficient
                        MeasureTheory.volume
                        (b i) γ) 
              ((LeanRidgelet.networkSynthesis
                        m s t σ)
                      γ =
                    f 
                  γ -
                      (LeanRidgelet.normalizedNetworkRightInverse
                          m s t σ)
                        f 
                    (↑(LeanRidgelet.networkSynthesis
                          m s t σ)).ker) 
                
                  (δ :
                    (LeanRidgelet.ParameterSpace
                        m s t)),
                  (LeanRidgelet.networkSynthesis
                          m s t σ)
                        δ =
                      f 
                    (LeanRidgelet.normalizedNetworkRightInverse
                              m s t σ)
                            f 
                        δ 
                      ((LeanRidgelet.normalizedNetworkRightInverse
                                m s t σ)
                              f =
                          δ 
                        (LeanRidgelet.normalizedNetworkRightInverse
                              m s t σ)
                            f =
                          δ)
    Manuscript Theorem 21: pointwise nullity, the unique basis expansion,
    the complete solution set, and the minimum-norm solution, collected from the coordinate theorems.
    
  • complete
    theorem LeanRidgelet.mem_ker_networkSynthesis_iff_fourierDilation (m : )
      [NeZero m] (s t : ) (σ : (LeanRidgelet.ActivationSpace s t))
      (γ : (LeanRidgelet.ParameterSpace m s t)) :
      γ  (↑(LeanRidgelet.networkSynthesis m s t σ)).ker 
        ∀ᵐ (x : LeanRidgelet.InputSpace m),
          (LeanRidgelet.activationFiberFunctional m s t σ)
              (((LeanRidgelet.fourierDilationTransform m s t) γ) x) =
            0
    theorem LeanRidgelet.mem_ker_networkSynthesis_iff_fourierDilation
      (m : ) [NeZero m] (s t : )
      (σ :
        (LeanRidgelet.ActivationSpace s t))
      (γ :
        (LeanRidgelet.ParameterSpace m s
            t)) :
      γ 
          (↑(LeanRidgelet.networkSynthesis m s
                t σ)).ker 
        ∀ᵐ (x : LeanRidgelet.InputSpace m),
          (LeanRidgelet.activationFiberFunctional
                m s t σ)
              (((LeanRidgelet.fourierDilationTransform
                        m s t)
                      γ)
                x) =
            0
    The null-space characterization with the manuscript unitary coordinate transform explicit. 
  • complete
    theorem LeanRidgelet.hasSum_ridgeletOperator_fiberCoefficient.{u_1}
      {ι : Type u_1} (m : ) [NeZero m] (s t : )
      (b : HilbertBasis ι  (LeanRidgelet.TargetSpace m))
      (γ : (LeanRidgelet.ParameterSpace m s t)) :
      HasSum
        (fun i 
          (LeanRidgelet.ridgeletOperator m s t
              (LeanRidgelet.fiberCoefficient MeasureTheory.volume (b i) γ))
            (b i))
        γ
    theorem LeanRidgelet.hasSum_ridgeletOperator_fiberCoefficient.{u_1}
      {ι : Type u_1} (m : ) [NeZero m]
      (s t : )
      (b :
        HilbertBasis ι 
          (LeanRidgelet.TargetSpace m))
      (γ :
        (LeanRidgelet.ParameterSpace m s
            t)) :
      HasSum
        (fun i 
          (LeanRidgelet.ridgeletOperator m s t
              (LeanRidgelet.fiberCoefficient
                MeasureTheory.volume (b i) γ))
            (b i))
        γ
    The coefficient-vector series expansion of a parameter distribution. 
  • complete
    theorem LeanRidgelet.networkSolution_iff_kernel_translate (m : ) [NeZero m]
      (s t : ) {σ : (LeanRidgelet.ActivationSpace s t)} ( : σ  0)
      (f : (LeanRidgelet.TargetSpace m))
      (γ : (LeanRidgelet.ParameterSpace m s t)) :
      (LeanRidgelet.networkSynthesis m s t σ) γ = f 
        γ - (LeanRidgelet.normalizedNetworkRightInverse m s t σ) f 
          (↑(LeanRidgelet.networkSynthesis m s t σ)).ker
    theorem LeanRidgelet.networkSolution_iff_kernel_translate
      (m : ) [NeZero m] (s t : )
      {σ :
        (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0)
      (f : (LeanRidgelet.TargetSpace m))
      (γ :
        (LeanRidgelet.ParameterSpace m s
            t)) :
      (LeanRidgelet.networkSynthesis m s t σ)
            γ =
          f 
        γ -
            (LeanRidgelet.normalizedNetworkRightInverse
                m s t σ)
              f 
          (↑(LeanRidgelet.networkSynthesis m s
                t σ)).ker
    Every solution is the normalized-adjoint solution plus a null component. 
  • complete
    theorem LeanRidgelet.normalizedNetworkRightInverse_unique_minimal (m : )
      [NeZero m] (s t : ) {σ : (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0) (f : (LeanRidgelet.TargetSpace m))
      (γ : (LeanRidgelet.ParameterSpace m s t)) :
      (LeanRidgelet.networkSynthesis m s t σ) γ = f 
        (LeanRidgelet.normalizedNetworkRightInverse m s t σ) f  γ 
          ((LeanRidgelet.normalizedNetworkRightInverse m s t σ) f = γ 
            (LeanRidgelet.normalizedNetworkRightInverse m s t σ) f = γ)
    theorem LeanRidgelet.normalizedNetworkRightInverse_unique_minimal
      (m : ) [NeZero m] (s t : )
      {σ :
        (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0)
      (f : (LeanRidgelet.TargetSpace m))
      (γ :
        (LeanRidgelet.ParameterSpace m s
            t)) :
      (LeanRidgelet.networkSynthesis m s t σ)
            γ =
          f 
        (LeanRidgelet.normalizedNetworkRightInverse
                  m s t σ)
                f 
            γ 
          ((LeanRidgelet.normalizedNetworkRightInverse
                    m s t σ)
                  f =
              γ 
            (LeanRidgelet.normalizedNetworkRightInverse
                  m s t σ)
                f =
              γ)
    The normalized-adjoint solution is the unique minimum-norm parameter solution. 
  • complete
    theorem LeanRidgelet.hasSum_unitaryRidgelet_kernelBasis.{u_1, u_2, u_3, u_4,
        u_5}
      {α : Type u_1} {H : Type u_2} {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α) [NormedAddCommGroup H]
      [InnerProductSpace  H] [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4} {κ : Type u_5}
      (T : G ≃ₗᵢ[] (LeanRidgelet.BochnerL2 α H μ)) (L : H →L[] )
      (b : HilbertBasis ι  (LeanRidgelet.L2 α μ))
      (d : HilbertBasis κ  (↑L).ker) (γ : G)
      ( : γ  (↑(LeanRidgelet.unitarySynthesis μ T L)).ker) :
      HasSum
        (fun p 
          (LeanRidgelet.unitaryNullDoubleCoefficients μ T L b d γ ) p 
            (LeanRidgelet.unitaryRidgelet μ T (d p.2)) (b p.1))
        γ
    theorem LeanRidgelet.hasSum_unitaryRidgelet_kernelBasis.{u_1,
        u_2, u_3, u_4, u_5}
      {α : Type u_1} {H : Type u_2}
      {G : Type u_3} [MeasurableSpace α]
      (μ : MeasureTheory.Measure α)
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H] [NormedAddCommGroup G]
      [InnerProductSpace  G] {ι : Type u_4}
      {κ : Type u_5}
      (T :
        G ≃ₗᵢ[]
          (LeanRidgelet.BochnerL2 α H μ))
      (L : H →L[] )
      (b :
        HilbertBasis ι 
          (LeanRidgelet.L2 α μ))
      (d : HilbertBasis κ  (↑L).ker) (γ : G)
      ( :
        γ 
          (↑(LeanRidgelet.unitarySynthesis μ T
                L)).ker) :
      HasSum
        (fun p 
          (LeanRidgelet.unitaryNullDoubleCoefficients
                  μ T L b d γ )
              p 
            (LeanRidgelet.unitaryRidgelet μ T
                (d p.2))
              (b p.1))
        γ
    Every abstract null parameter has the unconditional `I × J` ridgelet expansion associated
    with Hilbert bases of `L²(X)` and `ker L`. 

Section 6: Examples of Adjoint Ridgelet Functions: ReLU, Sigmoidal, and Gaussian Activations

The manuscript's Example 2 derives one-dimensional weak resolvent formulas for the adjoint ridgelet functions of ReLU, tanh, the Gaussian cumulative distribution function, and the Gaussian density. Lean currently formalizes membership and distributional realizations for several standard activations, but not these explicit Riesz-resolvent formulas.

Section 7: Further Developments: Finite-Width Approximation of Null Elements

Definition22
uses 0
Used by 3
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XL∃∀N

Let \mu be a finite complex Radon measure on parameter space and let \nu be a finite data measure. If the feature map \theta\mapsto\sigma(a\cdot x-b) has finite L^2(\nu) energy with respect to |\mu|, define S_\nu[\mu]:=\int\sigma(a\cdot{\,\cdot\,}-b)\,d\mu(a,b) \in L^2(\nu). This measure-valued domain is distinct from \mathcal G_{s,t}. No Lean declaration is linked because the Radon-measure construction has not yet been formalized.

Theorem23
uses 1used by 1L∃∀N

Let (\Theta,\mu) be a probability space, let H be a complex Hilbert space, and let \Phi:\Theta\to H and u:\Theta\to\mathbb C satisfy |u(\theta)|=1\ \text{a.e.},\qquad \int\|\Phi(\theta)\|^2d\mu(\theta)<\infty,\qquad \int u(\theta)\Phi(\theta)d\mu(\theta)=0. Then for every integer N\ge1 there exist \theta_1,\ldots,\theta_N\in\Theta such that \left\|\frac1N\sum_{j=1}^Nu(\theta_j)\Phi(\theta_j)\right\| \le\sqrt{\frac{\int\|\Phi\|^2d\mu}{N}}. The linked Lean declaration states this Hilbert-valued sampling conclusion. The manuscript's stronger Radon-measure, exact mean-square, and almost-sure convergence assertions are not part of that Lean statement.

Lean code for Theorem231 theorem, incomplete
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    contains sorry
    theorem LeanRidgelet.l2_theorem_five_normalized_finite_width_approximation.{u_1,
        u_2}
      {Θ : Type u_1} {H : Type u_2} [MeasurableSpace Θ]
      [NormedAddCommGroup H] [InnerProductSpace  H] [CompleteSpace H]
      (μ : MeasureTheory.Measure Θ) [MeasureTheory.IsProbabilityMeasure μ]
      (Φ : Θ  H) (u : Θ  ) (hu : ∀ᵐ (θ : Θ) μ, u θ = 1)
      (henergy : MeasureTheory.Integrable (fun θ  Φ θ ^ 2) μ)
      (hnull :  (θ : Θ), u θ  Φ θ μ = 0) (N : ) :
      0 < N 
         θ,
          (↑N)⁻¹   j, u (θ j)  Φ (θ j) 
            (( (x : Θ), Φ x ^ 2 μ) / N)
    theorem LeanRidgelet.l2_theorem_five_normalized_finite_width_approximation.{u_1,
        u_2}
      {Θ : Type u_1} {H : Type u_2}
      [MeasurableSpace Θ]
      [NormedAddCommGroup H]
      [InnerProductSpace  H]
      [CompleteSpace H]
      (μ : MeasureTheory.Measure Θ)
      [MeasureTheory.IsProbabilityMeasure μ]
      (Φ : Θ  H) (u : Θ  )
      (hu : ∀ᵐ (θ : Θ) μ, u θ = 1)
      (henergy :
        MeasureTheory.Integrable
          (fun θ  Φ θ ^ 2) μ)
      (hnull :  (θ : Θ), u θ  Φ θ μ = 0)
      (N : ) :
      0 < N 
         θ,
          (↑N)⁻¹   j, u (θ j)  Φ (θ j) 
            (( (x : Θ), Φ x ^ 2 μ) / N)
    Manuscript Theorem 23, in its Hilbert-valued sampling form: a centered
    normalized feature distribution has an `N`-term realization with `N⁻¹ᐟ²` output error.
    
Corollary24
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used by 0L∃∀N

Let m\ge1, s,t\in\mathbb R, and let 0\ne\sigma\in\mathcal A_{s,t}. Then there exist 0\ne f\in L^2(\mathbb R^m) and 0\ne h\in\mathcal H_{s,t} such that L_\sigma[h]=0,\qquad R_h[f]\in\ker S_\sigma. This is exactly the coordinate-level conclusion of the linked Lean declaration. The manuscript's additional passage from a Schwartz ridgelet element to a normalized Radon measure, under continuity, polynomial-growth, and compact-support assumptions, remains outside this statement.

Lean code for Corollary241 theorem, incomplete
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    contains sorry
    theorem LeanRidgelet.l2_corollary_one_discretizable_ridgelet_null_elements
      (m : ) [NeZero m] (s t : ) {σ : (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0) :
       f h,
        f  0 
          h  0 
            (LeanRidgelet.activationFiberFunctional m s t σ) h = 0 
              (LeanRidgelet.ridgeletOperator m s t h) f 
                (↑(LeanRidgelet.networkSynthesis m s t σ)).ker
    theorem LeanRidgelet.l2_corollary_one_discretizable_ridgelet_null_elements
      (m : ) [NeZero m] (s t : )
      {σ :
        (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0) :
       f h,
        f  0 
          h  0 
            (LeanRidgelet.activationFiberFunctional
                    m s t σ)
                  h =
                0 
              (LeanRidgelet.ridgeletOperator m
                    s t h)
                  f 
                (↑(LeanRidgelet.networkSynthesis
                      m s t σ)).ker
    Manuscript Corollary 24, at the present coordinate level: a nonzero null ridgelet element exists
    and is a candidate for the finite-width discretization theorem.
    
Proposition25
uses 0used by 0L∃∀N

Let m\ge0, a,x\in\mathbb R^m, and b\in\mathbb R. If \sigma is odd, then \sigma(a\cdot x-b)+\sigma((-a)\cdot x-(-b))=0, and if \sigma is even, the same two terms have difference zero. Moreover, for c_j\in\mathbb R, a_j\in\mathbb R^m, and b_j\in\mathbb R satisfying \sum_jc_ja_j=0,\qquad\sum_jc_jb_j=0, the ReLU features satisfy, for every x, \sum_jc_j\bigl((a_j\cdot x-b_j)_+-((-a_j)\cdot x-(-b_j))_+\bigr)=0. These three algebraic conclusions are the three conjuncts of the linked Lean declaration.

Lean code for Proposition251 theorem, incomplete
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    contains sorry
    theorem LeanRidgelet.l2_proposition_two_exact_finite_null_relations (m : ) :
      (∀ (σ :   ),
          (∀ (z : ), σ (-z) = -σ z) 
             (a x : LeanRidgelet.InputSpace m) (b : ),
              σ (inner  a x - b) + σ (inner  (-a) x - -b) = 0) 
        (∀ (σ :   ),
            (∀ (z : ), σ (-z) = σ z) 
               (a x : LeanRidgelet.InputSpace m) (b : ),
                σ (inner  a x - b) - σ (inner  (-a) x - -b) = 0) 
           (J : ) (c : Fin J  ) (a : Fin J  LeanRidgelet.InputSpace m)
            (b : Fin J  ),
             j, c j  a j = 0 
               j, c j * b j = 0 
                 (x : LeanRidgelet.InputSpace m),
                   j,
                      c j *
                        (max (inner  (a j) x - b j) 0 -
                          max (inner  (-a j) x - -b j) 0) =
                    0
    theorem LeanRidgelet.l2_proposition_two_exact_finite_null_relations
      (m : ) :
      (∀ (σ :   ),
          (∀ (z : ), σ (-z) = -σ z) 
            
              (a x :
                LeanRidgelet.InputSpace m)
              (b : ),
              σ (inner  a x - b) +
                  σ (inner  (-a) x - -b) =
                0) 
        (∀ (σ :   ),
            (∀ (z : ), σ (-z) = σ z) 
              
                (a x :
                  LeanRidgelet.InputSpace m)
                (b : ),
                σ (inner  a x - b) -
                    σ (inner  (-a) x - -b) =
                  0) 
           (J : ) (c : Fin J  )
            (a :
              Fin J 
                LeanRidgelet.InputSpace m)
            (b : Fin J  ),
             j, c j  a j = 0 
               j, c j * b j = 0 
                
                  (x :
                    LeanRidgelet.InputSpace
                      m),
                   j,
                      c j *
                        (max
                            (inner  (a j) x -
                              b j)
                            0 -
                          max
                            (inner  (-a j)
                                x -
                              -b j)
                            0) =
                    0
    Manuscript Proposition 25: parity and ReLU affine cancellation give
    exact finite null relations. 

Section 8: Further Developments: Numerical Illustration in Finite Networks

This section is a numerical illustration rather than a formal theorem. It discretizes continuous ridgelet null elements and distinguishes antipodal cancellation from a genuinely nontrivial null relation. No structural result depends on the experiment.

Section 9: Further Developments: Perturbative Readout of Null-Space Information

Theorem26
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used by 0L∃∀N

Let m\ge1, s,t\in\mathbb R, and let 0\ne\sigma\in\mathcal A_{s,t}. There exist orthonormal (h_i)_{i\in\mathbb N}\subset\ker L_\sigma and activations (\tau_i)_{i\in\mathbb N} satisfying L_{\tau_i}[h_j]=\delta_{ij}. For every f_0\in L^2(\mathbb R^m) and every sequence (f_i) with \sum_i\|f_i\|^2<\infty, there exists \gamma_{\mathrm{enc}}\in\mathcal G_{s,t} such that S_\sigma[\gamma_{\mathrm{enc}}]=f_0,\qquad \gamma_{\mathrm{enc}}-S_\sigma^\dagger[f_0]=\sum_iR_{h_i}[f_i],qquad S_{\tau_i}[\gamma_{\mathrm{enc}}]=f_i. For \delta\gamma_i:=S_\sigma^\dagger[f_i-f_0], one further has S_\sigma[\gamma_{\mathrm{enc}}+\delta\gamma_i]=f_i,qquad (I-P_\sigma)(\gamma_{\mathrm{enc}}+\delta\gamma_i) =(I-P_\sigma)\gamma_{\mathrm{enc}}. These are precisely the existential data and conclusions collected by the linked Lean statement; the manuscript's stronger uniqueness and exact-norm refinements are not asserted there.

Lean code for Theorem261 theorem, incomplete
  • theoremdefined in LeanRidgelet/OverviewL2.lean
    contains sorry
    theorem LeanRidgelet.l2_theorem_four_encoding_and_perturbative_readout (m : )
      [NeZero m] (s t : ) {σ : (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0) :
       h τ,
        Orthonormal  h 
          (∀ (i : ),
              (LeanRidgelet.activationFiberFunctional m s t σ) (h i) = 0) 
            (∀ (i j : ),
                (LeanRidgelet.activationFiberFunctional m s t (τ i)) (h j) =
                  if i = j then 1 else 0) 
               (f₀ : (LeanRidgelet.TargetSpace m))
                (f :   (LeanRidgelet.TargetSpace m)),
                (Summable fun i  f i ^ 2) 
                   γenc,
                    HasSum
                        (fun i 
                          (LeanRidgelet.ridgeletOperator m s t (h i)) (f i))
                        (γenc -
                          (LeanRidgelet.normalizedNetworkRightInverse m s t
                              σ)
                            f₀) 
                      (LeanRidgelet.networkSynthesis m s t σ) γenc = f₀ 
                         (i : ),
                          (LeanRidgelet.networkSynthesis m s t (τ i)) γenc =
                              f i 
                            have δγ :=
                              (LeanRidgelet.normalizedNetworkRightInverse m
                                  s t σ)
                                (f i - f₀);
                            (LeanRidgelet.networkSynthesis m s t σ)
                                  (γenc + δγ) =
                                f i 
                              (ContinuousLinearMap.id 
                                      (LeanRidgelet.ParameterSpace m s t) -
                                    LeanRidgelet.networkVisibleProjection m
                                      s t σ)
                                  (γenc + δγ) =
                                (ContinuousLinearMap.id 
                                      (LeanRidgelet.ParameterSpace m s t) -
                                    LeanRidgelet.networkVisibleProjection m
                                      s t σ)
                                  γenc
    theorem LeanRidgelet.l2_theorem_four_encoding_and_perturbative_readout
      (m : ) [NeZero m] (s t : )
      {σ :
        (LeanRidgelet.ActivationSpace s t)}
      ( : σ  0) :
       h τ,
        Orthonormal  h 
          (∀ (i : ),
              (LeanRidgelet.activationFiberFunctional
                    m s t σ)
                  (h i) =
                0) 
            (∀ (i j : ),
                (LeanRidgelet.activationFiberFunctional
                      m s t (τ i))
                    (h j) =
                  if i = j then 1 else 0) 
              
                (f₀ :
                  (LeanRidgelet.TargetSpace
                      m))
                (f :
                   
                    (LeanRidgelet.TargetSpace
                        m)),
                (Summable fun i  f i ^ 2) 
                   γenc,
                    HasSum
                        (fun i 
                          (LeanRidgelet.ridgeletOperator
                              m s t (h i))
                            (f i))
                        (γenc -
                          (LeanRidgelet.normalizedNetworkRightInverse
                              m s t σ)
                            f₀) 
                      (LeanRidgelet.networkSynthesis
                              m s t σ)
                            γenc =
                          f₀ 
                         (i : ),
                          (LeanRidgelet.networkSynthesis
                                  m s t (τ i))
                                γenc =
                              f i 
                            have δγ :=
                              (LeanRidgelet.normalizedNetworkRightInverse
                                  m s t σ)
                                (f i - f₀);
                            (LeanRidgelet.networkSynthesis
                                    m s t σ)
                                  (γenc +
                                    δγ) =
                                f i 
                              (ContinuousLinearMap.id
                                      
                                      (LeanRidgelet.ParameterSpace
                                          m s
                                          t) -
                                    LeanRidgelet.networkVisibleProjection
                                      m s t σ)
                                  (γenc +
                                    δγ) =
                                (ContinuousLinearMap.id
                                      
                                      (LeanRidgelet.ParameterSpace
                                          m s
                                          t) -
                                    LeanRidgelet.networkVisibleProjection
                                      m s t σ)
                                  γenc
    Manuscript Theorem 26: countably many null coefficient vectors admit dual
    readout activations, giving stable encoding and perturbative readout without changing the null
    component.
    

Section 10: Discussion

This section separates the proved continuous null-space structure, its finite-width traces, and the interpretation of null-space information. It introduces no additional numbered mathematical result.

Section 11: Conclusion

The conclusion summarizes the paper and likewise adds no numbered result.