English
In a normed space, PosDef (gram 𝕜 v) if and only if LinearIndependent 𝕜 v.
Русский
В нормированном пространстве PosDef(gram 𝕜 v) эквивалентно LinearIndependent(𝕜 v).
LaTeX
$$$ \text{PosDef }( \text{gram } 𝕜 v) \iff \text{LinearIndependent } 𝕜 v $$$
Lean4
theorem mem_span_gramSchmidt (f : ι → E) {i j : ι} (hij : i ≤ j) : f i ∈ span 𝕜 (gramSchmidt 𝕜 f '' Set.Iic j) :=
by
rw [gramSchmidt_def' 𝕜 f i]
simp_rw [starProjection_singleton]
exact
Submodule.add_mem _ (subset_span <| mem_image_of_mem _ hij)
(Submodule.sum_mem _ fun k hk =>
smul_mem (span 𝕜 (gramSchmidt 𝕜 f '' Set.Iic j)) _ <|
subset_span <| mem_image_of_mem (gramSchmidt 𝕜 f) <| (Finset.mem_Iio.1 hk).le.trans hij)