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Project-declaredLean 4.30.0 · mathlib@c5ea00351c28

Wkp U ibp tendsto

WkpU.ibp_tendsto

Plain-language statement

The IBP identity passes to the limit.

Exact Lean statement

lemma WkpU.ibp_tendsto [Fact (1 ≤ p)]
    {fₙ : ℕ → WkpU d k p U hU}
    (g : Lp ℝ p (μU d U))
    (hg : Tendsto (fun n => WkpU.toLp (fₙ n)) atTop (𝓝 g))
    (n : ℕ+) (hn : n ≤ k) (s : Fin n → Fin d)
    (g_ns : Lp ℝ p (μU d U))
    (hg_ns : Tendsto (fun j => WkpU.derivtoLp (fₙ j) n hn s) atTop (𝓝 g_ns))
    (ψ : (Fin d → ℝ) → ℝ) (hψ : ψ ∈ Cc_inftyU d U) :
    ∫ x, (g : (Fin d → ℝ) → ℝ) x • (iteratedFDeriv ℝ n ψ x) (unitSeq s) ∂ μU d U =
    (-1 : ℝ)^(n : ℕ) • ∫ x, ψ x • (g_ns : (Fin d → ℝ) → ℝ) x ∂ μU d U

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
lemma WkpU.ibp_tendsto [Fact (1  p)]    {fₙ :   WkpU d k p U hU}    (g : Lp  p (μU d U))    (hg : Tendsto (fun n => WkpU.toLp (fₙ n)) atTop (𝓝 g))    (n : +) (hn : n  k) (s : Fin n  Fin d)    (g_ns : Lp  p (μU d U))    (hg_ns : Tendsto (fun j => WkpU.derivtoLp (fₙ j) n hn s) atTop (𝓝 g_ns))    (ψ : (Fin d  )  ) (hψ : ψ  Cc_inftyU d U) :    ∫ x, (g : (Fin d  )  ) x • (iteratedFDeriv  n ψ x) (unitSeq s) ∂ μU d U =    (-1 : )^(n : ) • ∫ x, ψ x • (g_ns : (Fin d  )  ) x ∂ μU d U := by  have hconv := (Lp.tendsto_Lp_iff_tendsto_eLpNorm' _ g).mp hg  have hconv_ns := (Lp.tendsto_Lp_iff_tendsto_eLpNorm' _ g_ns).mp hg_ns  have hibp_j :  j,      ∫ x, (fₙ j : (Fin d  )  ) x • (iteratedFDeriv  n ψ x) (unitSeq s) ∂ μU d U =      (-1 : )^(n : ) • ∫ x, ψ x •        (WkpU.derivtoLp (fₙ j) n hn s : (Fin d  )  ) x ∂ μU d U := fun j => by    rw [WeakmultiderivU_spec U (fₙ j).val s (WkpU.hasWeakDeriv (fₙ j) n hn s) ψ hψ]    congr 1; apply integral_congr_ae    filter_upwards [(WkpU.weakDeriv_memLp (fₙ j) n hn s).coeFn_toLp] with x hx    simp only [WkpU.derivtoLp, WkpU.weakDeriv] at hx ; rw [hx]  have hlhs : Tendsto (fun j => ∫ x, (fₙ j : (Fin d  )  ) x •        (iteratedFDeriv  n ψ x) (unitSeq s) ∂ μU d U) atTop      (𝓝 (∫ x, (g : (Fin d  )  ) x •        (iteratedFDeriv  n ψ x) (unitSeq s) ∂ μU d U)) := by    have h := integral_tendsto_of_Lploc_tendsto Fact.out      (fun j => Lp.memLp (WkpU.toLp (fₙ j))) (Lp.memLp g)      (FderivCcinfty s hψ) hconv    simp_rw [ smul_eq_mul] at h    have hae :  j, (WkpU.toLp (fₙ j) : (Fin d  )  ) =ᵐ[μU d U]      (fₙ j : (Fin d  )  ) := fun j =>        (WkpU.memLp (fₙ j)).coeFn_toLp    exact h.congr fun j => integral_congr_ae      ((hae j).mono fun x hx => by simp [hx])  have hrhs : Tendsto (fun j =>        (-1 : )^(n : ) • ∫ x, ψ x •          (WkpU.derivtoLp (fₙ j) n hn s : (Fin d  )  ) x ∂ μU d U) atTop      (𝓝 ((-1 : )^(n : ) •        ∫ x, ψ x • (g_ns : (Fin d  )  ) x ∂ μU d U)) := by    apply Filter.Tendsto.const_smul    have h := integral_tendsto_of_Lploc_tendsto Fact.out      (fun j => Lp.memLp (WkpU.derivtoLp (fₙ j) n hn s))      (Lp.memLp g_ns) hψ hconv_ns    simp_rw [smul_eq_mul, mul_comm] at h     exact h  exact (tendsto_nhds_unique (hrhs.congr fun j => (hibp_j j).symm) hlhs).symm
Project
PDE
License
Apache-2.0
Commit
0ab5d79a0d7a
Source
PDE/SobolevSpace/SobolevSpaces.lean:803-847

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