English
The coordinate ring basis evaluated at n is equal to the generator raised to the n-th power, i.e., basis W' at n equals gen^n.
Русский
Основание координатного кольца, взятое в позиции n, равно генератору в степени n: basis W' n = gen^n.
LaTeX
$$$ CoordinateRing.basis W' n = (AdjoinRoot.powerBasis' monic_polynomial).gen^{(n : \mathbb{N})} $$$
Lean4
/-- The power basis `{1, Y}` for `R[W]` over `R[X]`. -/
protected noncomputable def basis : Basis (Fin 2) R[X] W'.CoordinateRing :=
(subsingleton_or_nontrivial R).by_cases (fun _ => default) fun _ =>
(AdjoinRoot.powerBasis' monic_polynomial).basis.reindex <| finCongr natDegree_polynomial