diff --git a/Nevanlinna/stronglyMeromorphic.lean b/Nevanlinna/stronglyMeromorphic.lean index c0aca67..d82645d 100644 --- a/Nevanlinna/stronglyMeromorphic.lean +++ b/Nevanlinna/stronglyMeromorphic.lean @@ -140,7 +140,20 @@ theorem localIdentity (hf : AnalyticAt ℂ f z₀) (hg : AnalyticAt ℂ g z₀) : f =ᶠ[𝓝[≠] z₀] g → f =ᶠ[𝓝 z₀] g := by - sorry + intro h + let Δ := f - g + have : AnalyticAt ℂ Δ z₀ := AnalyticAt.sub hf hg + have t₁ : Δ =ᶠ[𝓝[≠] z₀] 0 := by + exact Filter.eventuallyEq_iff_sub.mp h + + have : Δ =ᶠ[𝓝 z₀] 0 := by + rcases (AnalyticAt.eventually_eq_zero_or_eventually_ne_zero this) with h | h + · exact h + · have := Filter.EventuallyEq.eventually t₁ + let A := Filter.eventually_and.2 ⟨this, h⟩ + let _ := Filter.Eventually.exists A + tauto + exact Filter.eventuallyEq_iff_sub.mpr this theorem StronglyMeromorphicAt_of_makeStronglyMeromorphic @@ -179,7 +192,6 @@ theorem StronglyMeromorphicAt_of_makeStronglyMeromorphic simp by_cases h₃f : hf.order = (0 : ℤ) · let h₄f := (hf.order_eq_int_iff 0).1 h₃f - let G := Classical.choose h₄f simp [h₃f] obtain ⟨h₁G, h₂G, h₃G⟩ := Classical.choose_spec h₄f simp at h₃G @@ -187,7 +199,7 @@ theorem StronglyMeromorphicAt_of_makeStronglyMeromorphic rw [hn] rw [hn] at h₃g; simp at h₃g simp - have : g =ᶠ[𝓝 z₀] G := by + have : g =ᶠ[𝓝 z₀] (Classical.choose h₄f) := by apply localIdentity h₁g h₁G exact Filter.EventuallyEq.trans (Filter.EventuallyEq.symm h₃g) h₃G rw [Filter.EventuallyEq.eq_of_nhds this]