English
In the free monoid on α, for any x in α and xs in List α, the element corresponding to the list x :: xs equals the product of the images of x and xs: ofList (x :: xs) = of x * ofList xs.
Русский
В свободном моноиде на α для любых x ∈ α и xs ∈ List α элемент, соответствующий списку x :: xs, равен произведению образа x и образа xs: ofList (x :: xs) = of x * ofList xs.
LaTeX
$$$\\\\operatorname{ofList}(x \\\\colon xs) = \\\\operatorname{of} x \\\\cdot \\\\operatorname{ofList} xs$$$
Lean4
@[to_additive (attr := simp)]
theorem ofList_cons (x : α) (xs : List α) : ofList (x :: xs) = of x * ofList xs :=
rfl