English
Let bs be a list of elements of β. Then zipRight([], bs) equals the list formed by pairing None with each element of bs.
Русский
Пусть bs — список элементов β. Тогда zipRight([], bs) равен списку, получаемому сопоставлениемNone каждому элементу bs.
LaTeX
$$$ \operatorname{zipRight}(\varnothing, bs) = \operatorname{map}(b \mapsto (\mathrm{None}, b))\, bs$$$
Lean4
@[simp]
theorem zipRight_nil_left : zipRight ([] : List α) bs = bs.map fun b => (none, b) := by cases bs <;> rfl