English
If f tends to infinity, then for every c, eventually the values are not equal to c, even after composition with a certain mapping.
Русский
Если f → бесконечность, то для каждого c после некоторого момента значения не равны c.
LaTeX
$$$$\text{Given } hf : \operatorname{Tendsto} f\ l\ atTop, \; \forall c, \operatorname{Eventual}(x \neq c)\ l.$$$$
Lean4
protected theorem eventually_ne_atTop' [Preorder β] [NoTopOrder β] {f : α → β} {l : Filter α} (hf : Tendsto f l atTop)
(c : α) : ∀ᶠ x in l, x ≠ c :=
(hf.eventually_ne_atTop (f c)).mono fun _ => ne_of_apply_ne f