diff --git a/Nevanlinna/holomorphic_zero.lean b/Nevanlinna/holomorphic_zero.lean index d6021cc..50a7735 100644 --- a/Nevanlinna/holomorphic_zero.lean +++ b/Nevanlinna/holomorphic_zero.lean @@ -1,3 +1,4 @@ +import Mathlib.Topology.ContinuousOn import Mathlib.Analysis.Analytic.IsolatedZeros import Nevanlinna.holomorphic @@ -243,10 +244,28 @@ theorem discreteZeros theorem zeroDivisor_finiteOnCompact {f : ℂ → ℂ} - {s : Set ℂ} - (hs : IsCompact s) : - Set.Finite (s ∩ Function.support (zeroDivisor f)) := by - sorry + {U : Set ℂ} + (hU : IsPreconnected U) + (h₁f : AnalyticOn ℂ f U) + (h₂f : ∃ z ∈ U, f z ≠ 0) + (h₂U : IsCompact U) : + Set.Finite (U ∩ Function.support (zeroDivisor f)) := by + + have hinter : IsCompact (U ∩ Function.support (zeroDivisor f)) := by + apply IsCompact.of_isClosed_subset h₂U + rw [supportZeroSet] + apply h₁f.continuousOn.preimage_isClosed_of_isClosed + exact IsCompact.isClosed h₂U + exact isClosed_singleton + assumption + assumption + assumption + exact Set.inter_subset_left + + apply hinter.finite + apply DiscreteTopology.of_subset (s := Function.support (zeroDivisor f)) + exact discreteZeros (f := f) + exact Set.inter_subset_right theorem eliminatingZeros