English
For any α, 𝕜 with [RCLike 𝕜], Tendsto (f x : 𝕜) l (nhds (x : 𝕜)) ↔ Tendsto f l (nhds x).
Русский
Для любой пары α, 𝕜 с условием [RCLike 𝕜], Tendsto (f x : 𝕜) ⇄ Tendsto f.
LaTeX
$$$\\\\operatorname{Tendsto} (f x : 𝕜) \\\\ell (\\\\mathcal{N}(x : 𝕜)) \\\\iff \\\\operatorname{Tendsto} f \\\\ell (\\\\mathcal{N}(x))$$$
Lean4
theorem _root_.Filter.tendsto_ofReal_iff' {α 𝕜 : Type*} [RCLike 𝕜] {l : Filter α} {f : α → ℝ} {x : ℝ} :
Tendsto (fun x ↦ (f x : 𝕜)) l (𝓝 (x : 𝕜)) ↔ Tendsto f l (𝓝 x) :=
RCLike.isUniformEmbedding_ofReal.isClosedEmbedding.tendsto_nhds_iff.symm