English
For x ∈ U, the value of the global normal form at x is the same as the local normal form at x, i.e., (toMeromorphicNFOn f U) x = (toMeromorphicNFAt f x x).
Русский
Для x ∈ U значение глобальной нормальной формы в точке совпадает с локальной формой в этой точке: (toMeromorphicNFOn f U) x = (toMeromorphicNFAt f x x).
LaTeX
$$$(toMeromorphicNFOn\ f\ U)(x) = (toMeromorphicNFAt\ f\ x\ x)$$$
Lean4
/-- If `f` is meromorphic on `U` and `x ∈ U`, then conversion to normal form at `x`
and conversion to normal form on `U` agree at `x`.
-/
theorem toMeromorphicNFOn_eq_toMeromorphicNFAt (hf : MeromorphicOn f U) (hx : x ∈ U) :
toMeromorphicNFOn f U x = toMeromorphicNFAt f x x :=
by
apply Filter.EventuallyEq.eq_of_nhds (g := toMeromorphicNFAt f x)
simp [(toMeromorphicNFOn_eq_toMeromorphicNFAt_on_nhds hf hx).trans]