English
The map between orthonormal bases preserves the basis structure: mapping an ONB via a linear isometry yields a basis that is compatible with the map on bases.
Русский
Перемещение базиса через изометрическое отображение сохраняет структуру базиса.
LaTeX
$$$(b.map L).toBasis = b.toBasis$ under appropriate identifications$$
Lean4
@[simp]
protected theorem toBasis_map {G : Type*} [NormedAddCommGroup G] [InnerProductSpace 𝕜 G] (b : OrthonormalBasis ι 𝕜 E)
(L : E ≃ₗᵢ[𝕜] G) : (b.map L).toBasis = b.toBasis.map L.toLinearEquiv :=
rfl