English
For any integer n, the image of n under the canonical embedding equals n in the direct sum at index 0.
Русский
Для целого числа n образ подкладки совпадает с числом n в прямой сумме на индексе 0.
LaTeX
$$$\text{of}_A(0)\,n = n$$$
Lean4
/-- The `Semiring` structure derived from `GSemiring A`. -/
instance semiring : Semiring (A 0) :=
Function.Injective.semiring (of A 0) DFinsupp.single_injective (of A 0).map_zero (of_zero_one A) (of A 0).map_add
(of_zero_mul A) (fun _ _ ↦ (of A 0).map_nsmul _ _) (fun _ _ => of_zero_pow _ _ _) (of_natCast A)