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fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0

BoundedCompactSupport.mul_bdd_right''

Carleson.ToMathlib.BoundedCompactSupport · Carleson/ToMathlib/BoundedCompactSupport.lean:471 to 500

Mathematical statement

Exact Lean statement

lemma BoundedCompactSupport.mul_bdd_right'' (hf : BoundedCompactSupport f ν) {e : W → X}
    {g : W → 𝕜} (he : Continuous e) (he1 : Measure.QuasiMeasurePreserving e μ ν)
    (hg : AEStronglyMeasurable g μ)
    (hg1 : ∀ K : Set X, IsCompact K -> IsCompact (e ⁻¹' K ∩ tsupport g))
    (hg2 : ∀ (A : Set X) (_hA : IsBounded A), IsBounded (g '' (e ⁻¹' A))) :
    BoundedCompactSupport (fun x ↦ f (e x) * g x) μ where
  memLp_top

Complete declaration

Lean source

Canonical source
Full Lean sourceLean 4
lemma BoundedCompactSupport.mul_bdd_right'' (hf : BoundedCompactSupport f ν) {e : W  X}    {g : W  𝕜} (he : Continuous e) (he1 : Measure.QuasiMeasurePreserving e μ ν)    (hg : AEStronglyMeasurable g μ)    (hg1 :  K : Set X, IsCompact K -> IsCompact (e ⁻¹' K ∩ tsupport g))    (hg2 :  (A : Set X) (_hA : IsBounded A), IsBounded (g '' (e ⁻¹' A))) :    BoundedCompactSupport (fun x  f (e x) * g x) μ where  memLp_top := by    have := hf.memLp_top.ae_norm_le    set B := (eLpNorm f ⊤ ν).toReal    obtain C, hC := isBounded_iff_forall_norm_le.1      (hg2 (tsupport f) hf.hasCompactSupport.isBounded)    apply memLp_top_of_bound (C := max 0 B * max 0 C)    · exact (hf.mono_ac he1.absolutelyContinuous |>.aestronglyMeasurable.comp_measurable        he1.measurable).mul hg    filter_upwards [he1.ae this] with z hB    rw [norm_mul]    by_cases hz : z  e ⁻¹' tsupport f    · gcongr      · exact hB.trans (le_max_right ..)      refine hC _ ?_ |>.trans (le_max_right ..)      exact mem_image_of_mem g hz    · simp only [image_eq_zero_of_notMem_tsupport hz, norm_zero, zero_mul,        mul_nonneg (le_max_left 0 B) (le_max_left 0 C)]  hasCompactSupport := by    refine IsCompact.of_isClosed_subset (hg1 _ hf.hasCompactSupport)      (isClosed_tsupport fun x  f (e x) * g x) ?_    apply subset_inter ?_ tsupport_mul_subset_right    apply subset_trans (tsupport_mul_subset_left)    rw [tsupport, ((isClosed_tsupport f).preimage he ).closure_subset_iff]    exact fun _ hx  subset_closure hx