`BookProof.ChapterLaplacianProduct.sum_inner_mul_apply` [FiniteDimensional ℝ E] (L : E →L[ℝ] ℝ) (x : E) : ∑ i, ⟪x, (stdOrthonormalBasis ℝ E) i⟫ * L ((stdOrthonormalBasis ℝ E) i) =

Initializing...

`BookProof.ChapterLaplacianProduct.sum_inner_mul_apply` [FiniteDimensional ℝ E] (L : E →L[ℝ] ℝ) (x : E) : ∑ i, ⟪x, (stdOrthonormalBasis ℝ E) i⟫ * L ((stdOrthonormalBasis ℝ E) i) = · Prove2Me