English
The evaluation of the representation of toBasis on x at i equals the i-th coordinate of x in the basis representation.
Русский
Значение представления toBasis для x на i равно i-й координате x в представлении базиса.
LaTeX
$$b.toBasis.repr x i = b.repr x i$$
Lean4
@[simp]
protected theorem coe_toBasis_repr_apply (b : OrthonormalBasis ι 𝕜 E) (x : E) (i : ι) :
b.toBasis.repr x i = b.repr x i :=
by
rw [← Basis.equivFun_apply, OrthonormalBasis.coe_toBasis_repr]
-- This used to be `rw`, but we need `erw` after https://github.com/leanprover/lean4/pull/2644
erw [LinearIsometryEquiv.coe_toLinearEquiv]