Operator bounds extracted from actual source coordinate derivatives.
theorem
AVenhance.Infra.Section4.amnr_multilinear_norm_le_two_pow_basis
{F : Type u_1}
[NormedAddCommGroup F]
[NormedSpace ℝ F]
(n : ℕ)
(L : Homogenization.Vec 2 [×n]→L[ℝ] F)
{B : ℝ}
(hB : 0 ≤ B)
(h : ∀ (α : Fin n → Fin 2), ‖L fun (j : Fin n) => Homogenization.basisVec (α j)‖ ≤ B)
:
On the actual Vec 2 carrier, an n-linear operator costs at most
2^n times the largest coordinate evaluation. The target may be any normed
real space, including a higher derivative operator space.
theorem
AVenhance.Infra.Section4.amnrSpaceWord_ofFn_eq_iteratedFDeriv
{f : Homogenization.Vec 2 → ℝ}
(hf : ContDiff ℝ (↑⊤) f)
(n : ℕ)
(α : Fin n → Fin 2)
:
amnrSpaceWord (List.ofFn α) f = fun (x : Homogenization.Vec 2) =>
(iteratedFDeriv ℝ n f x) fun (j : Fin n) => Homogenization.basisVec (α j)
Tuple-indexed spatial words give the actual iterated derivative without introducing a separate higher-derivative carrier.
theorem
AVenhance.Infra.Section4.amnr_iteratedFDeriv_norm_le_of_spatial_words
{f : Homogenization.Vec 2 → ℝ}
(hf : ContDiff ℝ (↑⊤) f)
(n : ℕ)
(x : Homogenization.Vec 2)
{B : ℝ}
(hB : 0 ≤ B)
(hword : ∀ (α : List (Fin 2)), α.length = n → |amnrSpaceWord α f x| ≤ B)
:
Coordinate spatial-word bounds control the norm of the actual iterated Frechet derivative, uniformly over every derivative order.