The literal time-only K coefficient and the spatial flow correction remain separate in every differentiated forcing.
theorem
AVenhance.Infra.Section4.iterateSpatialWord_const
(c : ℝ)
(w : List (Fin 2))
:
(iterateSpatialWord w fun (x : Homogenization.Vec 2) => c) = fun (x : Homogenization.Vec 2) => if w = [] then c else 0
Positive-order spatial words annihilate a spatial constant.
theorem
AVenhance.Infra.Section4.iterateLowerWordFlux_constant
(B : Matrix (Fin 2) (Fin 2) ℝ)
(v : Homogenization.Vec 2 → ℝ)
(w : List (Fin 2))
:
A spatial constant matrix has no lower-order Leibniz flux.
theorem
AVenhance.Infra.Section4.iterateWordFlux_constant
(B : Matrix (Fin 2) (Fin 2) ℝ)
(v : Homogenization.Vec 2 → ℝ)
(w : List (Fin 2))
(x : Homogenization.Vec 2)
:
iterateWordFlux (fun (x : Homogenization.Vec 2) => B) v w x = B.mulVec (spaceGrad (iterateSpatialWord w v) x)
Only the principal flux survives for the time-only coefficient.
theorem
AVenhance.Infra.Section4.iterateWordFlux_add
{A B : Homogenization.Vec 2 → Matrix (Fin 2) (Fin 2) ℝ}
(hA : ContDiff ℝ (↑⊤) A)
(hB : ContDiff ℝ (↑⊤) B)
(v : Homogenization.Vec 2 → ℝ)
(w : List (Fin 2))
(x : Homogenization.Vec 2)
:
iterateWordFlux (fun (y : Homogenization.Vec 2) => A y + B y) v w x = iterateWordFlux A v w x + iterateWordFlux B v w x
The expanded flux is linear in its smooth matrix coefficient.
theorem
AVenhance.Infra.Section4.iterateWordFlux_TForcing_coefficient
{β : ℝ}
(I : Ingredients β)
{Φ : ℕ → ℝ → Homogenization.Vec 2 → ℝ}
(hΦ : IsStreamSeq I Φ)
(m : ℕ)
(κm κprev t : ℝ)
(hs : ContDiff ℝ (↑⊤) (I.sMat hΦ m κm t))
(v : Homogenization.Vec 2 → ℝ)
(w : List (Fin 2))
(x : Homogenization.Vec 2)
:
iterateWordFlux (fun (y : Homogenization.Vec 2) => I.Kmat κm m t - κprev • 1 + I.sMat hΦ m κm t y) v w x = (I.Kmat κm m t - κprev • 1).mulVec (spaceGrad (iterateSpatialWord w v) x) + iterateWordFlux (I.sMat hΦ m κm t) v w x
Exact forcing-flux decomposition for the literal iterate equation.