English
If a monotone f: β → α tends to a along atTop, then iSup f equals a.
Русский
Если монотонная функция f достигает предела a при atTop, тогда iSup f = a.
LaTeX
$$$ \operatorname{Tendsto} f \operatorname{atTop} (\nhds a) \Rightarrow \mathrm{iSup} f = a $$$
Lean4
theorem iSup_eq_of_tendsto {α β} [TopologicalSpace α] [CompleteLinearOrder α] [OrderTopology α] [Nonempty β]
[SemilatticeSup β] {f : β → α} {a : α} (hf : Monotone f) : Tendsto f atTop (𝓝 a) → iSup f = a :=
tendsto_nhds_unique (tendsto_atTop_iSup hf)