English
Conversion to normal form does not affect the divisor on U; i.e., divisor (toMeromorphicNFOn f U) U = divisor f U.
Русский
Преобразование к нормальной форме не изменяет дивизор на U: divisor (toMeromorphicNFOn f U) U = divisor f U.
LaTeX
$$$\operatorname{divisor}(toMeromorphicNFOn\ f\ U, U) = \operatorname{divisor}(f, U)$$$
Lean4
/-- Conversion of normal form does not affect divisors.
-/
@[simp]
theorem divisor_of_toMeromorphicNFOn (hf : MeromorphicOn f U) : divisor (toMeromorphicNFOn f U) U = divisor f U :=
by
ext z
by_cases hz : z ∈ U <;> simp [hf, (meromorphicNFOn_toMeromorphicNFOn f U).meromorphicOn, hz]