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AlexKontorovich/PrimeNumberTheoremAnd
Source indexedlemma ยท leanprover/lean4:v4.32.0

MeromorphicOn.exists_nonzero_seq_divisor_support_diff_zero

PrimeNumberTheoremAnd.Mathlib.Analysis.Meromorphic.DivisorSupport ยท PrimeNumberTheoremAnd/Mathlib/Analysis/Meromorphic/DivisorSupport.lean:112 to 135

Mathematical statement

Exact Lean statement

lemma exists_nonzero_seq_divisor_support_diff_zero [HereditarilyLindelofSpace ๐•œ]
    {f : ๐•œ โ†’ E} {U : Set ๐•œ} :
    โˆƒ a : โ„• โ†’ ๐•œ,
      (โˆ€ n, a n โ‰  0) โˆง (MeromorphicOn.divisor f U).support \ {0} โІ Set.range a

Complete declaration

Lean source

Canonical source
Full Lean sourceLean 4
lemma exists_nonzero_seq_divisor_support_diff_zero [HereditarilyLindelofSpace ๐•œ]    {f : ๐•œ โ†’ E} {U : Set ๐•œ} :    โˆƒ a : โ„• โ†’ ๐•œ,      (โˆ€ n, a n โ‰  0) โˆง (MeromorphicOn.divisor f U).support \ {0} โІ Set.range a := by  classical  set s : Set ๐•œ := (MeromorphicOn.divisor f U).support \ {0}  by_cases hs : s.Nonempty  ยท have hs_count : s.Countable := by      have hsup : (MeromorphicOn.divisor f U).support.Countable :=        MeromorphicOn.divisor_support_countable (f := f) (U := U)      refine hsup.mono ?_      intro x hx      exact hx.1    rcases hs_count.exists_eq_range hs with โŸจa, haโŸฉ    refine โŸจa, ?_, ?_โŸฉ    ยท intro n      have : a n โˆˆ s := by        simp [ha]      exact fun h0 => this.2 (by simpa [Set.mem_singleton_iff] using h0)    ยท simp [ha]  ยท refine โŸจfun _ => (1 : ๐•œ), ?_, ?_โŸฉ    ยท intro _; simp    ยท have : s = โˆ… := Set.not_nonempty_iff_eq_empty.1 hs      simp [this]