English
The map of a replicated element is the replication of the mapped element: map f (replicate k a) = replicate k (f a).
Русский
Отображение f распределяет повторения: map f (replicate k a) = replicate k (f a).
LaTeX
$$$$ \\mathrm{map} f (\\mathrm{replicate} k\\ a) = \\mathrm{replicate} k (f\\ a) $$$$
Lean4
@[simp]
theorem map_replicate (f : α → β) (k : ℕ) (a : α) : (replicate k a).map f = replicate k (f a) := by
simp only [← coe_replicate, map_coe, List.map_replicate]