Zulip Chat Archive
Stream: Is there code for X?
Topic: Integration by parts for `fderiv`
Tomas Skrivan (Jun 25 2025 at 10:21):
I want a generalization of integration by parts docs#MeasureTheory.integral_bilinear_hasDerivAt_right_eq_neg_left_of_integrable but for fderiv instead.
Something like this (not sure about the exact assumptions on X):
import Mathlib
open MeasureTheory
variable
{X E F G : Type*}
[NormedAddCommGroup X] [NormedSpace ℝ X] [FiniteDimensional ℝ X] [MeasurableSpace X]
[NormedAddCommGroup E] [NormedSpace ℝ E]
[NormedAddCommGroup F] [NormedSpace ℝ F] [NormedAddCommGroup G] [NormedSpace ℝ G]
{μ : Measure X} [μ.IsAddHaarMeasure]
{L : E →L[ℝ] F →L[ℝ] G} {u : X → E} {v : X → F} {u' : X → X →L[ℝ] E} {v' : X → X →L[ℝ] F}
{m n : G}
theorem integral_bilinear_hasDerivAt_right_eq_neg_left_of_integrable (dx : X)
(hu : ∀ x, HasFDerivAt u (u' x) x) (hv : ∀ x, HasFDerivAt v (v' x) x)
(huv' : Integrable (fun x ↦ L (u x) (v' x dx)) μ) (hu'v : Integrable (fun x ↦ L (u' x dx) (v x)) μ)
(huv : Integrable (fun x ↦ L (u x) (v x)) μ) :
∫ (x : X), L (u x) (v' x dx) ∂μ = - ∫ (x : X), L (u' x dx) (v x) ∂μ := sorry
I'm not sure what is the best approach here and I want the result be general enough such that I can have things like X = ℝ × EuclideanSpace (Fin 10) ℝ.
Tomas Skrivan (Jun 25 2025 at 10:29):
Ohh never mind, there is docs#integral_mul_fderiv_eq_neg_fderiv_mul_of_integrable
Last updated: Dec 20 2025 at 21:32 UTC