English
If two functions agree on a punctured neighborhood, then MeromorphicAt f x holds iff MeromorphicAt g x holds.
Русский
Если две функции совпадают на punctured окрестности, тогда MeromorphicAt f x верна тогда и только тогда, когда MeromorphicAt g x верна.
LaTeX
$$$MeromorphicAt f x \\to MeromorphicAt g x \\Leftrightarrow MeromorphicAt g x$$$
Lean4
/-- If two functions agree on a punctured neighborhood, then one is meromorphic iff the other is so.
-/
theorem meromorphicAt_congr {f g : 𝕜 → E} {x : 𝕜} (h : f =ᶠ[𝓝[≠] x] g) : MeromorphicAt f x ↔ MeromorphicAt g x :=
⟨fun hf ↦ hf.congr h, fun hg ↦ hg.congr h.symm⟩