English
A variant stating the equivalence for l.map f with a primed form identical to cauchy_map_iff.
Русский
Вариант, формулирующий эквивалентность для l.map f в аналогичном виде к cauchy_map_iff.
LaTeX
$$$ {l:\text{Filter }\beta} \;{f:\beta\to\alpha}:\; \text{Cauchy}(\text{Filter.map } f\ l) \iff \text{NeBot}(l) \land \text{Tendsto}(\lambda p:β×β, (f\ p.1, f\ p.2))\ (l×ˢ l) (𝓤\_α)$$$
Lean4
theorem cauchy_map_iff' {l : Filter β} [hl : NeBot l] {f : β → α} :
Cauchy (l.map f) ↔ Tendsto (fun p : β × β => (f p.1, f p.2)) (l ×ˢ l) (𝓤 α) :=
cauchy_map_iff.trans <| and_iff_right hl