English
If an orthogonal basis has no self-orthogonal vectors, then the bilinear form is right-separating.
Русский
Если базис не имеет self-orthogonal элементов, форма правосторонне разделяет.
LaTeX
$$B.SeparatingRight$$
Lean4
/-- Given an orthogonal basis with respect to a bilinear map, the bilinear map is right-separating
if the basis has no elements which are self-orthogonal. -/
theorem separatingRight_iff_not_isOrtho_basis_self [NoZeroSMulDivisors R M₁] {B : M →ₗ[R] M →ₗ[R] M₁} (v : Basis n R M)
(hO : B.IsOrthoᵢ v) (h : ∀ i, ¬B.IsOrtho (v i) (v i)) : B.SeparatingRight :=
by
rw [isOrthoᵢ_flip] at hO
rw [← flip_separatingLeft]
refine IsOrthoᵢ.separatingLeft_of_not_isOrtho_basis_self v hO fun i ↦ ?_
rw [isOrtho_flip]
exact h i