English
Bijectivity of PLift.map f is equivalent to bijectivity of f.
Русский
Биективность отображения PLift.map f эквивалентна биективности f.
LaTeX
$$$\\forall {\\alpha \\beta} {f : \\alpha \\rightarrow \\beta}, \\operatorname{Bijective}(\\mathrm{PLift.map} f) \\Leftrightarrow \\operatorname{Bijective}(f)$$$
Lean4
@[simp]
theorem map_bijective : Bijective (PLift.map f) ↔ Bijective f :=
(down_bijective.of_comp_iff _).trans <| Bijective.of_comp_iff' up_bijective _