fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0
MeasureTheory.memLp_of_memLp_le_of_memLp_ge
Carleson.ToMathlib.RealInterpolation.Misc · Carleson/ToMathlib/RealInterpolation/Misc.lean:890 to 907
Mathematical statement
Exact Lean statement
lemma memLp_of_memLp_le_of_memLp_ge {f : α → ε} [ContinuousAdd ε]
{r : ℝ≥0∞} (hp : 0 < p) (hr' : q ∈ Icc p r)
(hf : MemLp f p μ) (hf' : MemLp f r μ) : MemLp f q μComplete declaration
Lean source
Full Lean sourceLean 4
lemma memLp_of_memLp_le_of_memLp_ge {f : α → ε} [ContinuousAdd ε] {r : ℝ≥0∞} (hp : 0 < p) (hr' : q ∈ Icc p r) (hf : MemLp f p μ) (hf' : MemLp f r μ) : MemLp f q μ := by by_cases p_ne_top : p = ⊤ · rw [p_ne_top] at hf convert hf rw [eq_top_iff] convert hr'.1 exact p_ne_top.symm set C := (1 : ℝ≥0∞) have h : MemLp (trnc ⊤ f C) q μ := trunc_Lp_Lq_higher ⟨hp, hr'.1⟩ hf (by norm_num) have h' : MemLp (trnc ⊥ f C) q μ := by by_cases hr : r = ⊤ · exact memLp_truncCompl_of_memLp_top (hr ▸ hf') <| distribution_lt_top hf hp p_ne_top (by norm_num) exact truncCompl_Lp_Lq_lower hr ⟨hp.trans_le hr'.1, hr'.2⟩ (by norm_num) hf' have : f = (trnc ⊤ f C) + (trnc ⊥ f C) := trunc_add_truncCompl.symm rw [this] exact h.add h'