diff --git a/Nevanlinna/stronglyMeromorphic.lean b/Nevanlinna/stronglyMeromorphic.lean index 6f9ca10..c1a4a90 100644 --- a/Nevanlinna/stronglyMeromorphic.lean +++ b/Nevanlinna/stronglyMeromorphic.lean @@ -4,7 +4,6 @@ import Nevanlinna.mathlibAddOn /- Strongly MeromorphicAt -/ - def StronglyMeromorphicAt (f : ℂ → ℂ) (z₀ : ℂ) := @@ -63,6 +62,25 @@ theorem StronglyMeromorphicAt.analytic exact h₁g +/- Analytic functions are strongly meromorphic -/ +theorem AnalyticAt.stronglyMeromorphicAt + {f : ℂ → ℂ} + {z₀ : ℂ} + (h₁f : AnalyticAt ℂ f z₀) : + StronglyMeromorphicAt f z₀ := by + by_cases h₂f : h₁f.order = ⊤ + · rw [AnalyticAt.order_eq_top_iff] at h₂f + tauto + · have : h₁f.order ≠ ⊤ := h₂f + rw [← ENat.coe_toNat_eq_self] at this + rw [eq_comm, AnalyticAt.order_eq_nat_iff] at this + right + use h₁f.order.toNat + obtain ⟨g, h₁g, h₂g, h₃g⟩ := this + use g + tauto + + /- Make strongly MeromorphicAt -/ noncomputable def MeromorphicAt.makeStronglyMeromorphicAt {f : ℂ → ℂ}