fpvandoorn/carleson
Source indexedlemma Β· leanprover/lean4:v4.32.0
exists_mem_auxπ
Carleson.Discrete.ForestComplement Β· Carleson/Discrete/ForestComplement.lean:26 to 45
Mathematical statement
Exact Lean statement
lemma exists_mem_auxπ {i : Grid X} (hi : 0 < volume (G β© i)) : β k, i β auxπ (k + 1)Complete declaration
Lean source
Full Lean sourceLean 4
lemma exists_mem_auxπ {i : Grid X} (hi : 0 < volume (G β© i)) : β k, i β auxπ (k + 1) := by have vlt : volume (i : Set X) < β€ := volume_coeGrid_lt_top have one_le_quot : 1 β€ volume (i : Set X) / volume (G β© i) := by rw [ENNReal.le_div_iff_mul_le (Or.inl hi.ne') (Or.inr vlt.ne), one_mul] exact measure_mono inter_subset_right have quot_ne_top : volume (i : Set X) / volume (G β© i) β β€ := by rw [Ne, ENNReal.div_eq_top, not_or, not_and_or, not_and_or] exact β¨Or.inr hi.ne', Or.inl vlt.neβ© have ornz : 0 < (volume (i : Set X) / volume (G β© i)).toReal := ENNReal.toReal_pos (zero_lt_one.trans_le one_le_quot).ne' quot_ne_top let k : β := Real.logb 2 (volume (i : Set X) / volume (G β© i)).toReal use βkββ, i, le_rfl nth_rw 1 [β ENNReal.mul_lt_mul_iff_right (show 2 ^ (βkββ + 1) β 0 by simp) (by simp), β mul_assoc, β ENNReal.rpow_natCast, β ENNReal.rpow_intCast, β ENNReal.rpow_add _ _ (by simp) (by simp)] rw [Int.cast_neg, Int.cast_natCast, add_neg_cancel, ENNReal.rpow_zero, one_mul, β ENNReal.div_lt_iff (Or.inl hi.ne') (Or.inr vlt.ne), β ENNReal.ofReal_toReal quot_ne_top, β @ENNReal.ofReal_toReal (2 ^ (βkββ + 1)) (by simp), ENNReal.ofReal_lt_ofReal_iff (by simp), ENNReal.toReal_pow, ENNReal.toReal_ofNat, β Real.rpow_natCast, β Real.logb_lt_iff_lt_rpow one_lt_two ornz] exact Nat.lt_succ_floor k