English
If f is continuous and f l l', then Tendsto f from l.lift' closure to l'.lift' closure.
Русский
Если f непрерывна и Tendsto f l l', то Tendsto f (l.lift' closure) (l'.lift' closure).
LaTeX
$$$\\text{Continuous}(f) \\Rightarrow \\forall l\,l',\\ Tendsto\\ f\\ l\\ l' \\Rightarrow \\ Tendsto\\ f\\ (l.lift'\\text{ closure})\\ (l'.lift'\\text{ closure})$$$
Lean4
theorem lift'_closure (hf : Continuous f) {l l'} (h : Tendsto f l l') :
Tendsto f (l.lift' closure) (l'.lift' closure) :=
tendsto_lift'.2 fun s hs ↦ by filter_upwards [mem_lift' (h hs)] using (mapsTo_preimage _ _).closure hf