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complex.orthonormal_basis_one_I_repr_symm_apply (x : euclidean_space ℝ (fin 2)) : complex.orthonormal_basis_one_I.repr.symm x = (x 0) + (x 1) * I
rfl
lemma
complex.orthonormal_basis_one_I_repr_symm_apply
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "euclidean_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
complex.to_basis_orthonormal_basis_one_I : complex.orthonormal_basis_one_I.to_basis = complex.basis_one_I
basis.to_basis_to_orthonormal_basis _ _
lemma
complex.to_basis_orthonormal_basis_one_I
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "basis.to_basis_to_orthonormal_basis", "complex.basis_one_I" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
complex.coe_orthonormal_basis_one_I : (complex.orthonormal_basis_one_I : (fin 2) → ℂ) = ![1, I]
by simp [complex.orthonormal_basis_one_I]
lemma
complex.coe_orthonormal_basis_one_I
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "complex.orthonormal_basis_one_I" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
complex.isometry_of_orthonormal (v : orthonormal_basis (fin 2) ℝ F) : ℂ ≃ₗᵢ[ℝ] F
complex.orthonormal_basis_one_I.repr.trans v.repr.symm
def
complex.isometry_of_orthonormal
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "orthonormal_basis" ]
The isometry between `ℂ` and a two-dimensional real inner product space given by a basis.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
complex.map_isometry_of_orthonormal (v : orthonormal_basis (fin 2) ℝ F) (f : F ≃ₗᵢ[ℝ] F') : complex.isometry_of_orthonormal (v.map f) = (complex.isometry_of_orthonormal v).trans f
by simp [complex.isometry_of_orthonormal, linear_isometry_equiv.trans_assoc, orthonormal_basis.map]
lemma
complex.map_isometry_of_orthonormal
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "complex.isometry_of_orthonormal", "linear_isometry_equiv.trans_assoc", "orthonormal_basis", "orthonormal_basis.map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
complex.isometry_of_orthonormal_symm_apply (v : orthonormal_basis (fin 2) ℝ F) (f : F) : (complex.isometry_of_orthonormal v).symm f = (v.to_basis.coord 0 f : ℂ) + (v.to_basis.coord 1 f : ℂ) * I
by simp [complex.isometry_of_orthonormal]
lemma
complex.isometry_of_orthonormal_symm_apply
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "complex.isometry_of_orthonormal", "orthonormal_basis" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
complex.isometry_of_orthonormal_apply (v : orthonormal_basis (fin 2) ℝ F) (z : ℂ) : complex.isometry_of_orthonormal v z = z.re • v 0 + z.im • v 1
by simp [complex.isometry_of_orthonormal, ← v.sum_repr_symm]
lemma
complex.isometry_of_orthonormal_apply
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "complex.isometry_of_orthonormal", "orthonormal_basis" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthonormal_basis.to_matrix_orthonormal_basis_mem_unitary : a.to_basis.to_matrix b ∈ matrix.unitary_group ι 𝕜
begin rw matrix.mem_unitary_group_iff', ext i j, convert a.repr.inner_map_map (b i) (b j), rw orthonormal_iff_ite.mp b.orthonormal i j, refl, end
lemma
orthonormal_basis.to_matrix_orthonormal_basis_mem_unitary
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "matrix.mem_unitary_group_iff'", "matrix.unitary_group" ]
The change-of-basis matrix between two orthonormal bases `a`, `b` is a unitary matrix.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthonormal_basis.det_to_matrix_orthonormal_basis : ‖a.to_basis.det b‖ = 1
begin have : (norm_sq (a.to_basis.det b) : 𝕜) = 1, { simpa [is_R_or_C.mul_conj] using (matrix.det_of_mem_unitary (a.to_matrix_orthonormal_basis_mem_unitary b)).2 }, norm_cast at this, rwa [← sqrt_norm_sq_eq_norm, sqrt_eq_one], end
lemma
orthonormal_basis.det_to_matrix_orthonormal_basis
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "is_R_or_C.mul_conj", "matrix.det_of_mem_unitary" ]
The determinant of the change-of-basis matrix between two orthonormal bases `a`, `b` has unit length.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthonormal_basis.to_matrix_orthonormal_basis_mem_orthogonal : a.to_basis.to_matrix b ∈ matrix.orthogonal_group ι ℝ
a.to_matrix_orthonormal_basis_mem_unitary b
lemma
orthonormal_basis.to_matrix_orthonormal_basis_mem_orthogonal
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "matrix.orthogonal_group" ]
The change-of-basis matrix between two orthonormal bases `a`, `b` is an orthogonal matrix.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthonormal_basis.det_to_matrix_orthonormal_basis_real : a.to_basis.det b = 1 ∨ a.to_basis.det b = -1
begin rw ← sq_eq_one_iff, simpa [unitary, sq] using matrix.det_of_mem_unitary (a.to_matrix_orthonormal_basis_mem_unitary b) end
lemma
orthonormal_basis.det_to_matrix_orthonormal_basis_real
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "matrix.det_of_mem_unitary", "sq_eq_one_iff", "unitary" ]
The determinant of the change-of-basis matrix between two orthonormal bases `a`, `b` is ±1.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
direct_sum.is_internal.collected_orthonormal_basis (hV : orthogonal_family 𝕜 (λ i, A i) (λ i, (A i).subtypeₗᵢ)) [decidable_eq ι] (hV_sum : direct_sum.is_internal (λ i, A i)) {α : ι → Type*} [Π i, fintype (α i)] (v_family : Π i, orthonormal_basis (α i) 𝕜 (A i)) : orthonormal_basis (Σ i, α i) 𝕜 E
(hV_sum.collected_basis (λ i, (v_family i).to_basis)).to_orthonormal_basis $ by simpa using hV.orthonormal_sigma_orthonormal (show (∀ i, orthonormal 𝕜 (v_family i).to_basis), by simp)
def
direct_sum.is_internal.collected_orthonormal_basis
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "direct_sum.is_internal", "fintype", "orthogonal_family", "orthonormal", "orthonormal_basis" ]
Given an internal direct sum decomposition of a module `M`, and an orthonormal basis for each of the components of the direct sum, the disjoint union of these orthonormal bases is an orthonormal basis for `M`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
direct_sum.is_internal.collected_orthonormal_basis_mem [decidable_eq ι] (h : direct_sum.is_internal A) {α : ι → Type*} [Π i, fintype (α i)] (hV : orthogonal_family 𝕜 (λ i, A i) (λ i, (A i).subtypeₗᵢ)) (v : Π i, orthonormal_basis (α i) 𝕜 (A i)) (a : Σ i, α i) : h.collected_orthonormal_basis hV v a ∈ A a.1
by simp [direct_sum.is_internal.collected_orthonormal_basis]
lemma
direct_sum.is_internal.collected_orthonormal_basis_mem
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "direct_sum.is_internal", "direct_sum.is_internal.collected_orthonormal_basis", "fintype", "orthogonal_family", "orthonormal_basis" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.orthonormal.exists_orthonormal_basis_extension (hv : orthonormal 𝕜 (coe : v → E)) : ∃ {u : finset E} (b : orthonormal_basis u 𝕜 E), v ⊆ u ∧ ⇑b = coe
begin obtain ⟨u₀, hu₀s, hu₀, hu₀_max⟩ := exists_maximal_orthonormal hv, rw maximal_orthonormal_iff_orthogonal_complement_eq_bot hu₀ at hu₀_max, have hu₀_finite : u₀.finite := hu₀.linear_independent.finite, let u : finset E := hu₀_finite.to_finset, let fu : ↥u ≃ ↥u₀ := equiv.cast (congr_arg coe_sort hu₀_finite...
lemma
orthonormal.exists_orthonormal_basis_extension
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "equiv.cast", "exists_maximal_orthonormal", "finset", "maximal_orthonormal_iff_orthogonal_complement_eq_bot", "orthonormal", "orthonormal_basis" ]
In a finite-dimensional `inner_product_space`, any orthonormal subset can be extended to an orthonormal basis.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.orthonormal.exists_orthonormal_basis_extension_of_card_eq {ι : Type*} [fintype ι] (card_ι : finrank 𝕜 E = fintype.card ι) {v : ι → E} {s : set ι} (hv : orthonormal 𝕜 (s.restrict v)) : ∃ b : orthonormal_basis ι 𝕜 E, ∀ i ∈ s, b i = v i
begin have hsv : injective (s.restrict v) := hv.linear_independent.injective, have hX : orthonormal 𝕜 (coe : set.range (s.restrict v) → E), { rwa orthonormal_subtype_range hsv }, obtain ⟨Y, b₀, hX, hb₀⟩ := hX.exists_orthonormal_basis_extension, have hιY : fintype.card ι = Y.card, { refine (card_ι.symm.tran...
lemma
orthonormal.exists_orthonormal_basis_extension_of_card_eq
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "finite_dimensional.finrank_eq_card_finset_basis", "fintype", "fintype.card", "orthonormal", "orthonormal_basis", "orthonormal_subtype_range", "set.inj_on", "set.inj_on_iff_injective", "set.range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.exists_orthonormal_basis : ∃ (w : finset E) (b : orthonormal_basis w 𝕜 E), ⇑b = (coe : w → E)
let ⟨w, hw, hw', hw''⟩ := (orthonormal_empty 𝕜 E).exists_orthonormal_basis_extension in ⟨w, hw, hw''⟩
lemma
exists_orthonormal_basis
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "finset", "orthonormal_basis", "orthonormal_empty" ]
A finite-dimensional inner product space admits an orthonormal basis.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
std_orthonormal_basis : orthonormal_basis (fin (finrank 𝕜 E)) 𝕜 E
begin let b := classical.some (classical.some_spec $ exists_orthonormal_basis 𝕜 E), rw [finrank_eq_card_basis b.to_basis], exact b.reindex (fintype.equiv_fin_of_card_eq rfl), end
def
std_orthonormal_basis
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "exists_orthonormal_basis", "fintype.equiv_fin_of_card_eq", "orthonormal_basis" ]
A finite-dimensional `inner_product_space` has an orthonormal basis.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthonormal_basis_one_dim (b : orthonormal_basis ι ℝ ℝ) : ⇑b = (λ _, (1 : ℝ)) ∨ ⇑b = (λ _, (-1 : ℝ))
begin haveI : unique ι, from b.to_basis.unique, have : b default = 1 ∨ b default = - 1, { have : ‖b default‖ = 1, from b.orthonormal.1 _, rwa [real.norm_eq_abs, abs_eq (zero_le_one : (0 : ℝ) ≤ 1)] at this }, rw eq_const_of_unique b, refine this.imp _ _; simp, end
lemma
orthonormal_basis_one_dim
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "abs_eq", "eq_const_of_unique", "orthonormal_basis", "real.norm_eq_abs", "unique", "zero_le_one" ]
An orthonormal basis of `ℝ` is made either of the vector `1`, or of the vector `-1`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
direct_sum.is_internal.sigma_orthonormal_basis_index_equiv (hV' : orthogonal_family 𝕜 (λ i, V i) (λ i, (V i).subtypeₗᵢ)) : (Σ i, fin (finrank 𝕜 (V i))) ≃ fin n
let b := hV.collected_orthonormal_basis hV' (λ i, (std_orthonormal_basis 𝕜 (V i))) in fintype.equiv_fin_of_card_eq $ (finite_dimensional.finrank_eq_card_basis b.to_basis).symm.trans hn
def
direct_sum.is_internal.sigma_orthonormal_basis_index_equiv
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "finite_dimensional.finrank_eq_card_basis", "fintype.equiv_fin_of_card_eq", "orthogonal_family", "std_orthonormal_basis" ]
Exhibit a bijection between `fin n` and the index set of a certain basis of an `n`-dimensional inner product space `E`. This should not be accessed directly, but only via the subsequent API.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
direct_sum.is_internal.subordinate_orthonormal_basis (hV' : orthogonal_family 𝕜 (λ i, V i) (λ i, (V i).subtypeₗᵢ)) : orthonormal_basis (fin n) 𝕜 E
((hV.collected_orthonormal_basis hV' (λ i, (std_orthonormal_basis 𝕜 (V i)))).reindex (hV.sigma_orthonormal_basis_index_equiv hn hV'))
def
direct_sum.is_internal.subordinate_orthonormal_basis
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "orthogonal_family", "orthonormal_basis", "reindex", "std_orthonormal_basis" ]
An `n`-dimensional `inner_product_space` equipped with a decomposition as an internal direct sum has an orthonormal basis indexed by `fin n` and subordinate to that direct sum.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
direct_sum.is_internal.subordinate_orthonormal_basis_index (a : fin n) (hV' : orthogonal_family 𝕜 (λ i, V i) (λ i, (V i).subtypeₗᵢ)) : ι
((hV.sigma_orthonormal_basis_index_equiv hn hV').symm a).1
def
direct_sum.is_internal.subordinate_orthonormal_basis_index
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "orthogonal_family" ]
An `n`-dimensional `inner_product_space` equipped with a decomposition as an internal direct sum has an orthonormal basis indexed by `fin n` and subordinate to that direct sum. This function provides the mapping by which it is subordinate.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
direct_sum.is_internal.subordinate_orthonormal_basis_subordinate (a : fin n) (hV' : orthogonal_family 𝕜 (λ i, V i) (λ i, (V i).subtypeₗᵢ)) : (hV.subordinate_orthonormal_basis hn hV' a) ∈ V (hV.subordinate_orthonormal_basis_index hn a hV')
by simpa only [direct_sum.is_internal.subordinate_orthonormal_basis, orthonormal_basis.coe_reindex, direct_sum.is_internal.subordinate_orthonormal_basis_index] using hV.collected_orthonormal_basis_mem hV' (λ i, (std_orthonormal_basis 𝕜 (V i))) ((hV.sigma_orthonormal_basis_index_equiv hn hV').symm a)
lemma
direct_sum.is_internal.subordinate_orthonormal_basis_subordinate
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "direct_sum.is_internal.subordinate_orthonormal_basis", "direct_sum.is_internal.subordinate_orthonormal_basis_index", "orthogonal_family", "std_orthonormal_basis" ]
The basis constructed in `orthogonal_family.subordinate_orthonormal_basis` is subordinate to the `orthogonal_family` in question.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthonormal_basis.from_orthogonal_span_singleton (n : ℕ) [fact (finrank 𝕜 E = n + 1)] {v : E} (hv : v ≠ 0) : orthonormal_basis (fin n) 𝕜 (𝕜 ∙ v)ᗮ
(std_orthonormal_basis _ _).reindex $ fin_congr $ finrank_orthogonal_span_singleton hv
def
orthonormal_basis.from_orthogonal_span_singleton
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "fact", "fin_congr", "finrank_orthogonal_span_singleton", "orthonormal_basis", "reindex", "std_orthonormal_basis" ]
Given a natural number `n` one less than the `finrank` of a finite-dimensional inner product space, there exists an isometry from the orthogonal complement of a nonzero singleton to `euclidean_space 𝕜 (fin n)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry.extend (L : S →ₗᵢ[𝕜] V): V →ₗᵢ[𝕜] V
begin -- Build an isometry from Sᗮ to L(S)ᗮ through euclidean_space let d := finrank 𝕜 Sᗮ, have dim_S_perp : finrank 𝕜 Sᗮ = d := rfl, let LS := L.to_linear_map.range, have E : Sᗮ ≃ₗᵢ[𝕜] LSᗮ, { have dim_LS_perp : finrank 𝕜 LSᗮ = d, calc finrank 𝕜 LSᗮ = finrank 𝕜 V - finrank 𝕜 LS : by simp only ...
def
linear_isometry.extend
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "add_tsub_cancel_left", "complete_space", "continuous_linear_map.coe_coe", "continuous_linear_map.to_linear_map_eq_coe", "fin_congr", "finite_dimensional.complete", "linear_isometry.coe_comp", "linear_isometry.coe_to_linear_map", "linear_isometry.norm_map", "linear_map.add_apply", "linear_map.co...
Let `S` be a subspace of a finite-dimensional complex inner product space `V`. A linear isometry mapping `S` into `V` can be extended to a full isometry of `V`. TODO: The case when `S` is a finite-dimensional subspace of an infinite-dimensional `V`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry.extend_apply (L : S →ₗᵢ[𝕜] V) (s : S): L.extend s = L s
begin haveI : complete_space S := finite_dimensional.complete 𝕜 S, simp only [linear_isometry.extend, continuous_linear_map.to_linear_map_eq_coe, ←linear_isometry.coe_to_linear_map], simp only [add_right_eq_self, linear_isometry.coe_to_linear_map, linear_isometry_equiv.coe_to_linear_isometry, linear_isom...
lemma
linear_isometry.extend_apply
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "complete_space", "continuous_linear_map.coe_coe", "continuous_linear_map.to_linear_map_eq_coe", "finite_dimensional.complete", "linear_isometry.coe_comp", "linear_isometry.coe_to_linear_map", "linear_isometry.extend", "linear_isometry_equiv.coe_to_linear_isometry", "linear_isometry_equiv.map_eq_zer...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_euclidean_lin : matrix m n 𝕜 ≃ₗ[𝕜] (euclidean_space 𝕜 n →ₗ[𝕜] euclidean_space 𝕜 m)
matrix.to_lin' ≪≫ₗ linear_equiv.arrow_congr (pi_Lp.linear_equiv _ 𝕜 (λ _ : n, 𝕜)).symm (pi_Lp.linear_equiv _ 𝕜 (λ _ : m, 𝕜)).symm
def
matrix.to_euclidean_lin
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "euclidean_space", "linear_equiv.arrow_congr", "matrix", "matrix.to_lin'", "pi_Lp.linear_equiv" ]
`matrix.to_lin'` adapted for `euclidean_space 𝕜 _`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_euclidean_lin_pi_Lp_equiv_symm (A : matrix m n 𝕜) (x : n → 𝕜) : A.to_euclidean_lin ((pi_Lp.equiv _ _).symm x) = (pi_Lp.equiv _ _).symm (A.to_lin' x)
rfl
lemma
matrix.to_euclidean_lin_pi_Lp_equiv_symm
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "matrix", "pi_Lp.equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pi_Lp_equiv_to_euclidean_lin (A : matrix m n 𝕜) (x : euclidean_space 𝕜 n) : pi_Lp.equiv _ _ (A.to_euclidean_lin x) = A.to_lin' (pi_Lp.equiv _ _ x)
rfl
lemma
matrix.pi_Lp_equiv_to_euclidean_lin
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "euclidean_space", "matrix", "pi_Lp.equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_euclidean_lin_eq_to_lin : (to_euclidean_lin : matrix m n 𝕜 ≃ₗ[𝕜] _) = matrix.to_lin (pi_Lp.basis_fun _ _ _) (pi_Lp.basis_fun _ _ _)
rfl
lemma
matrix.to_euclidean_lin_eq_to_lin
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "matrix", "matrix.to_lin", "pi_Lp.basis_fun" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inner_matrix_row_row [fintype n] (A B : matrix m n 𝕜) (i j : m) : ⟪A i, B j⟫ₑ = (B ⬝ Aᴴ) j i
by simp_rw [euclidean_space.inner_pi_Lp_equiv_symm, matrix.mul_apply', matrix.dot_product_comm, matrix.conj_transpose_apply, pi.star_def]
lemma
inner_matrix_row_row
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "euclidean_space.inner_pi_Lp_equiv_symm", "fintype", "matrix", "matrix.conj_transpose_apply", "matrix.dot_product_comm", "matrix.mul_apply'", "pi.star_def" ]
The inner product of a row of `A` and a row of `B` is an entry of `B ⬝ Aᴴ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inner_matrix_col_col [fintype m] (A B : matrix m n 𝕜) (i j : n) : ⟪Aᵀ i, Bᵀ j⟫ₑ = (Aᴴ ⬝ B) i j
rfl
lemma
inner_matrix_col_col
analysis.inner_product_space
src/analysis/inner_product_space/pi_L2.lean
[ "analysis.inner_product_space.projection", "analysis.normed_space.pi_Lp", "linear_algebra.finite_dimensional", "linear_algebra.unitary_group" ]
[ "fintype", "matrix" ]
The inner product of a column of `A` and a column of `B` is an entry of `Aᴴ ⬝ B`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive (T : E →L[𝕜] E) : Prop
is_self_adjoint T ∧ ∀ x, 0 ≤ T.re_apply_inner_self x
def
continuous_linear_map.is_positive
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[ "is_self_adjoint" ]
A continuous linear endomorphism `T` of a Hilbert space is **positive** if it is self adjoint and `∀ x, 0 ≤ re ⟪T x, x⟫`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive.is_self_adjoint {T : E →L[𝕜] E} (hT : is_positive T) : is_self_adjoint T
hT.1
lemma
continuous_linear_map.is_positive.is_self_adjoint
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[ "is_self_adjoint" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive.inner_nonneg_left {T : E →L[𝕜] E} (hT : is_positive T) (x : E) : 0 ≤ re ⟪T x, x⟫
hT.2 x
lemma
continuous_linear_map.is_positive.inner_nonneg_left
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive.inner_nonneg_right {T : E →L[𝕜] E} (hT : is_positive T) (x : E) : 0 ≤ re ⟪x, T x⟫
by rw inner_re_symm; exact hT.inner_nonneg_left x
lemma
continuous_linear_map.is_positive.inner_nonneg_right
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[ "inner_re_symm" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive_zero : is_positive (0 : E →L[𝕜] E)
begin refine ⟨is_self_adjoint_zero _, λ x, _⟩, change 0 ≤ re ⟪_, _⟫, rw [zero_apply, inner_zero_left, zero_hom_class.map_zero] end
lemma
continuous_linear_map.is_positive_zero
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[ "inner_zero_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive_one : is_positive (1 : E →L[𝕜] E)
⟨is_self_adjoint_one _, λ x, inner_self_nonneg⟩
lemma
continuous_linear_map.is_positive_one
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive.add {T S : E →L[𝕜] E} (hT : T.is_positive) (hS : S.is_positive) : (T + S).is_positive
begin refine ⟨hT.is_self_adjoint.add hS.is_self_adjoint, λ x, _⟩, rw [re_apply_inner_self, add_apply, inner_add_left, map_add], exact add_nonneg (hT.inner_nonneg_left x) (hS.inner_nonneg_left x) end
lemma
continuous_linear_map.is_positive.add
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[ "inner_add_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive.conj_adjoint {T : E →L[𝕜] E} (hT : T.is_positive) (S : E →L[𝕜] F) : (S ∘L T ∘L S†).is_positive
begin refine ⟨hT.is_self_adjoint.conj_adjoint S, λ x, _⟩, rw [re_apply_inner_self, comp_apply, ← adjoint_inner_right], exact hT.inner_nonneg_left _ end
lemma
continuous_linear_map.is_positive.conj_adjoint
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive.adjoint_conj {T : E →L[𝕜] E} (hT : T.is_positive) (S : F →L[𝕜] E) : (S† ∘L T ∘L S).is_positive
begin convert hT.conj_adjoint (S†), rw adjoint_adjoint end
lemma
continuous_linear_map.is_positive.adjoint_conj
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive.conj_orthogonal_projection (U : submodule 𝕜 E) {T : E →L[𝕜] E} (hT : T.is_positive) [complete_space U] : (U.subtypeL ∘L orthogonal_projection U ∘L T ∘L U.subtypeL ∘L orthogonal_projection U).is_positive
begin have := hT.conj_adjoint (U.subtypeL ∘L orthogonal_projection U), rwa (orthogonal_projection_is_self_adjoint U).adjoint_eq at this end
lemma
continuous_linear_map.is_positive.conj_orthogonal_projection
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[ "complete_space", "orthogonal_projection", "orthogonal_projection_is_self_adjoint", "submodule" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive.orthogonal_projection_comp {T : E →L[𝕜] E} (hT : T.is_positive) (U : submodule 𝕜 E) [complete_space U] : (orthogonal_projection U ∘L T ∘L U.subtypeL).is_positive
begin have := hT.conj_adjoint (orthogonal_projection U : E →L[𝕜] U), rwa [U.adjoint_orthogonal_projection] at this, end
lemma
continuous_linear_map.is_positive.orthogonal_projection_comp
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[ "complete_space", "orthogonal_projection", "submodule" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_positive_iff_complex (T : E' →L[ℂ] E') : is_positive T ↔ ∀ x, (re ⟪T x, x⟫_ℂ : ℂ) = ⟪T x, x⟫_ℂ ∧ 0 ≤ re ⟪T x, x⟫_ℂ
begin simp_rw [is_positive, forall_and_distrib, is_self_adjoint_iff_is_symmetric, linear_map.is_symmetric_iff_inner_map_self_real, conj_eq_iff_re], refl end
lemma
continuous_linear_map.is_positive_iff_complex
analysis.inner_product_space
src/analysis/inner_product_space/positive.lean
[ "analysis.inner_product_space.adjoint" ]
[ "forall_and_distrib", "linear_map.is_symmetric_iff_inner_map_self_real" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_norm_eq_infi_of_complete_convex {K : set F} (ne : K.nonempty) (h₁ : is_complete K) (h₂ : convex ℝ K) : ∀ u : F, ∃ v ∈ K, ‖u - v‖ = ⨅ w : K, ‖u - w‖
assume u, begin let δ := ⨅ w : K, ‖u - w‖, letI : nonempty K := ne.to_subtype, have zero_le_δ : 0 ≤ δ := le_cinfi (λ _, norm_nonneg _), have δ_le : ∀ w : K, δ ≤ ‖u - w‖, from cinfi_le ⟨0, set.forall_range_iff.2 $ λ _, norm_nonneg _⟩, have δ_le' : ∀ w ∈ K, δ ≤ ‖u - w‖ := assume w hw, δ_le ⟨w, hw⟩, -- Ste...
theorem
exists_norm_eq_infi_of_complete_convex
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "add_halves", "add_smul", "cauchy_seq", "cauchy_seq_iff_le_tendsto_0", "cauchy_seq_tendsto_of_is_complete", "cinfi_le", "continuous", "continuous.comp", "continuous_const", "continuous_id", "convex", "exists_lt_of_cinfi_lt", "is_complete", "le_cinfi", "le_rfl", "mul_assoc", "mul_le_m...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_eq_infi_iff_real_inner_le_zero {K : set F} (h : convex ℝ K) {u : F} {v : F} (hv : v ∈ K) : ‖u - v‖ = (⨅ w : K, ‖u - w‖) ↔ ∀ w ∈ K, ⟪u - v, w - v⟫_ℝ ≤ 0
iff.intro begin assume eq w hw, let δ := ⨅ w : K, ‖u - w‖, let p := ⟪u - v, w - v⟫_ℝ, let q := ‖w - v‖^2, letI : nonempty K := ⟨⟨v, hv⟩⟩, have zero_le_δ : 0 ≤ δ, apply le_cinfi, intro, exact norm_nonneg _, have δ_le : ∀ w : K, δ ≤ ‖u - w‖, assume w, apply cinfi_le, use (0:ℝ), rintros _ ⟨_, rfl⟩, exact...
theorem
norm_eq_infi_iff_real_inner_le_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "abs_of_pos", "by_contradiction", "cinfi_le", "convex", "div_mul_cancel", "div_pos", "inner_smul_right", "le_cinfi", "mul_le_mul_of_nonneg_right", "mul_self_le_mul_self", "nonneg_le_nonneg_of_sq_le_sq", "nonneg_of_mul_nonneg_right", "norm_smul", "norm_sub_sq", "one_smul", "ring", "sm...
Characterization of minimizers for the projection on a convex set in a real inner product space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_norm_eq_infi_of_complete_subspace (h : is_complete (↑K : set E)) : ∀ u : E, ∃ v ∈ K, ‖u - v‖ = ⨅ w : (K : set E), ‖u - w‖
begin letI : inner_product_space ℝ E := inner_product_space.is_R_or_C_to_real 𝕜 E, letI : module ℝ E := restrict_scalars.module ℝ 𝕜 E, let K' : submodule ℝ E := submodule.restrict_scalars ℝ K, exact exists_norm_eq_infi_of_complete_convex ⟨0, K'.zero_mem⟩ h K'.convex end
theorem
exists_norm_eq_infi_of_complete_subspace
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "exists_norm_eq_infi_of_complete_convex", "inner_product_space", "inner_product_space.is_R_or_C_to_real", "is_complete", "module", "submodule", "submodule.restrict_scalars" ]
Existence of projections on complete subspaces. Let `u` be a point in an inner product space, and let `K` be a nonempty complete subspace. Then there exists a (unique) `v` in `K` that minimizes the distance `‖u - v‖` to `u`. This point `v` is usually called the orthogonal projection of `u` onto `K`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_eq_infi_iff_real_inner_eq_zero (K : submodule ℝ F) {u : F} {v : F} (hv : v ∈ K) : ‖u - v‖ = (⨅ w : (↑K : set F), ‖u - w‖) ↔ ∀ w ∈ K, ⟪u - v, w⟫_ℝ = 0
iff.intro begin assume h, have h : ∀ w ∈ K, ⟪u - v, w - v⟫_ℝ ≤ 0, { rwa [norm_eq_infi_iff_real_inner_le_zero] at h, exacts [K.convex, hv] }, assume w hw, have le : ⟪u - v, w⟫_ℝ ≤ 0, let w' := w + v, have : w' ∈ K := submodule.add_mem _ hw hv, have h₁ := h w' this, have h₂ : w' - v = w, simp on...
theorem
norm_eq_infi_iff_real_inner_eq_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "inner_neg_right", "norm_eq_infi_iff_real_inner_le_zero", "submodule", "submodule.add_mem", "submodule.convex", "submodule.neg_mem", "submodule.sub_mem" ]
Characterization of minimizers in the projection on a subspace, in the real case. Let `u` be a point in a real inner product space, and let `K` be a nonempty subspace. Then point `v` minimizes the distance `‖u - v‖` over points in `K` if and only if for all `w ∈ K`, `⟪u - v, w⟫ = 0` (i.e., `u - v` is orthogonal to the ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_eq_infi_iff_inner_eq_zero {u : E} {v : E} (hv : v ∈ K) : ‖u - v‖ = (⨅ w : K, ‖u - w‖) ↔ ∀ w ∈ K, ⟪u - v, w⟫ = 0
begin letI : inner_product_space ℝ E := inner_product_space.is_R_or_C_to_real 𝕜 E, letI : module ℝ E := restrict_scalars.module ℝ 𝕜 E, let K' : submodule ℝ E := K.restrict_scalars ℝ, split, { assume H, have A : ∀ w ∈ K, re ⟪u - v, w⟫ = 0 := (norm_eq_infi_iff_real_inner_eq_zero K' hv).1 H, assume w h...
theorem
norm_eq_infi_iff_inner_eq_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "inner_product_space", "inner_product_space.is_R_or_C_to_real", "inner_smul_right", "module", "norm_eq_infi_iff_real_inner_eq_zero", "real_inner_eq_re_inner", "submodule" ]
Characterization of minimizers in the projection on a subspace. Let `u` be a point in an inner product space, and let `K` be a nonempty subspace. Then point `v` minimizes the distance `‖u - v‖` over points in `K` if and only if for all `w ∈ K`, `⟪u - v, w⟫ = 0` (i.e., `u - v` is orthogonal to the subspace `K`)
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_fn (v : E)
(exists_norm_eq_infi_of_complete_subspace K (complete_space_coe_iff_is_complete.mp ‹_›) v).some
def
orthogonal_projection_fn
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "exists_norm_eq_infi_of_complete_subspace" ]
The orthogonal projection onto a complete subspace, as an unbundled function. This definition is only intended for use in setting up the bundled version `orthogonal_projection` and should not be used once that is defined.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_fn_mem (v : E) : orthogonal_projection_fn K v ∈ K
(exists_norm_eq_infi_of_complete_subspace K (complete_space_coe_iff_is_complete.mp ‹_›) v).some_spec.some
lemma
orthogonal_projection_fn_mem
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "exists_norm_eq_infi_of_complete_subspace", "orthogonal_projection_fn" ]
The unbundled orthogonal projection is in the given subspace. This lemma is only intended for use in setting up the bundled version and should not be used once that is defined.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_fn_inner_eq_zero (v : E) : ∀ w ∈ K, ⟪v - orthogonal_projection_fn K v, w⟫ = 0
begin rw ←norm_eq_infi_iff_inner_eq_zero K (orthogonal_projection_fn_mem v), exact (exists_norm_eq_infi_of_complete_subspace K (complete_space_coe_iff_is_complete.mp ‹_›) v).some_spec.some_spec end
lemma
orthogonal_projection_fn_inner_eq_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "exists_norm_eq_infi_of_complete_subspace", "orthogonal_projection_fn", "orthogonal_projection_fn_mem" ]
The characterization of the unbundled orthogonal projection. This lemma is only intended for use in setting up the bundled version and should not be used once that is defined.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_orthogonal_projection_fn_of_mem_of_inner_eq_zero {u v : E} (hvm : v ∈ K) (hvo : ∀ w ∈ K, ⟪u - v, w⟫ = 0) : orthogonal_projection_fn K u = v
begin rw [←sub_eq_zero, ←@inner_self_eq_zero 𝕜], have hvs : orthogonal_projection_fn K u - v ∈ K := submodule.sub_mem K (orthogonal_projection_fn_mem u) hvm, have huo : ⟪u - orthogonal_projection_fn K u, orthogonal_projection_fn K u - v⟫ = 0 := orthogonal_projection_fn_inner_eq_zero u _ hvs, have huv :...
lemma
eq_orthogonal_projection_fn_of_mem_of_inner_eq_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "inner_self_eq_zero", "inner_sub_left", "orthogonal_projection_fn", "orthogonal_projection_fn_inner_eq_zero", "orthogonal_projection_fn_mem", "submodule.sub_mem" ]
The unbundled orthogonal projection is the unique point in `K` with the orthogonality property. This lemma is only intended for use in setting up the bundled version and should not be used once that is defined.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_fn_norm_sq (v : E) : ‖v‖ * ‖v‖ = ‖v - (orthogonal_projection_fn K v)‖ * ‖v - (orthogonal_projection_fn K v)‖ + ‖orthogonal_projection_fn K v‖ * ‖orthogonal_projection_fn K v‖
begin set p := orthogonal_projection_fn K v, have h' : ⟪v - p, p⟫ = 0, { exact orthogonal_projection_fn_inner_eq_zero _ _ (orthogonal_projection_fn_mem v) }, convert norm_add_sq_eq_norm_sq_add_norm_sq_of_inner_eq_zero (v - p) p h' using 2; simp, end
lemma
orthogonal_projection_fn_norm_sq
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "norm_add_sq_eq_norm_sq_add_norm_sq_of_inner_eq_zero", "orthogonal_projection_fn", "orthogonal_projection_fn_inner_eq_zero", "orthogonal_projection_fn_mem" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection : E →L[𝕜] K
linear_map.mk_continuous { to_fun := λ v, ⟨orthogonal_projection_fn K v, orthogonal_projection_fn_mem v⟩, map_add' := λ x y, begin have hm : orthogonal_projection_fn K x + orthogonal_projection_fn K y ∈ K := submodule.add_mem K (orthogonal_projection_fn_mem x) (orthogonal_projection_fn_mem y), ...
def
orthogonal_projection
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "eq_orthogonal_projection_fn_of_mem_of_inner_eq_zero", "inner_add_left", "inner_smul_left", "le_of_pow_le_pow", "linear_map.coe_mk", "linear_map.mk_continuous", "mul_zero", "one_mul", "orthogonal_projection_fn", "orthogonal_projection_fn_inner_eq_zero", "orthogonal_projection_fn_mem", "orthogo...
The orthogonal projection onto a complete subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_fn_eq (v : E) : orthogonal_projection_fn K v = (orthogonal_projection K v : E)
rfl
lemma
orthogonal_projection_fn_eq
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "orthogonal_projection", "orthogonal_projection_fn" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_inner_eq_zero (v : E) : ∀ w ∈ K, ⟪v - orthogonal_projection K v, w⟫ = 0
orthogonal_projection_fn_inner_eq_zero v
lemma
orthogonal_projection_inner_eq_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "orthogonal_projection", "orthogonal_projection_fn_inner_eq_zero" ]
The characterization of the orthogonal projection.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sub_orthogonal_projection_mem_orthogonal (v : E) : v - orthogonal_projection K v ∈ Kᗮ
begin intros w hw, rw inner_eq_zero_symm, exact orthogonal_projection_inner_eq_zero _ _ hw end
lemma
sub_orthogonal_projection_mem_orthogonal
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "inner_eq_zero_symm", "orthogonal_projection", "orthogonal_projection_inner_eq_zero" ]
The difference of `v` from its orthogonal projection onto `K` is in `Kᗮ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_orthogonal_projection_of_mem_of_inner_eq_zero {u v : E} (hvm : v ∈ K) (hvo : ∀ w ∈ K, ⟪u - v, w⟫ = 0) : (orthogonal_projection K u : E) = v
eq_orthogonal_projection_fn_of_mem_of_inner_eq_zero hvm hvo
lemma
eq_orthogonal_projection_of_mem_of_inner_eq_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "eq_orthogonal_projection_fn_of_mem_of_inner_eq_zero", "orthogonal_projection" ]
The orthogonal projection is the unique point in `K` with the orthogonality property.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_minimal {U : submodule 𝕜 E} [complete_space U] (y : E) : ‖y - orthogonal_projection U y‖ = ⨅ x : U, ‖y - x‖
begin rw norm_eq_infi_iff_inner_eq_zero _ (submodule.coe_mem _), exact orthogonal_projection_inner_eq_zero _ end
lemma
orthogonal_projection_minimal
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "norm_eq_infi_iff_inner_eq_zero", "orthogonal_projection", "orthogonal_projection_inner_eq_zero", "submodule", "submodule.coe_mem" ]
The orthogonal projection of `y` on `U` minimizes the distance `‖y - x‖` for `x ∈ U`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_orthogonal_projection_of_eq_submodule {K' : submodule 𝕜 E} [complete_space K'] (h : K = K') (u : E) : (orthogonal_projection K u : E) = (orthogonal_projection K' u : E)
begin change orthogonal_projection_fn K u = orthogonal_projection_fn K' u, congr, exact h end
lemma
eq_orthogonal_projection_of_eq_submodule
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "orthogonal_projection", "orthogonal_projection_fn", "submodule" ]
The orthogonal projections onto equal subspaces are coerced back to the same point in `E`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_mem_subspace_eq_self (v : K) : orthogonal_projection K v = v
by { ext, apply eq_orthogonal_projection_of_mem_of_inner_eq_zero; simp }
lemma
orthogonal_projection_mem_subspace_eq_self
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "eq_orthogonal_projection_of_mem_of_inner_eq_zero", "orthogonal_projection" ]
The orthogonal projection sends elements of `K` to themselves.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_eq_self_iff {v : E} : (orthogonal_projection K v : E) = v ↔ v ∈ K
begin refine ⟨λ h, _, λ h, eq_orthogonal_projection_of_mem_of_inner_eq_zero h _⟩, { rw ← h, simp }, { simp } end
lemma
orthogonal_projection_eq_self_iff
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "eq_orthogonal_projection_of_mem_of_inner_eq_zero", "orthogonal_projection" ]
A point equals its orthogonal projection if and only if it lies in the subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry.map_orthogonal_projection {E E' : Type*} [normed_add_comm_group E] [normed_add_comm_group E'] [inner_product_space 𝕜 E] [inner_product_space 𝕜 E'] (f : E →ₗᵢ[𝕜] E') (p : submodule 𝕜 E) [complete_space p] (x : E) : f (orthogonal_projection p x) = orthogonal_projection (p.map f.to_linear_map...
begin refine (eq_orthogonal_projection_of_mem_of_inner_eq_zero _ $ λ y hy, _).symm, refine submodule.apply_coe_mem_map _ _, rcases hy with ⟨x', hx', rfl : f x' = y⟩, rw [← f.map_sub, f.inner_map_map, orthogonal_projection_inner_eq_zero x x' hx'] end
lemma
linear_isometry.map_orthogonal_projection
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "eq_orthogonal_projection_of_mem_of_inner_eq_zero", "inner_product_space", "normed_add_comm_group", "orthogonal_projection", "orthogonal_projection_inner_eq_zero", "submodule", "submodule.apply_coe_mem_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry.map_orthogonal_projection' {E E' : Type*} [normed_add_comm_group E] [normed_add_comm_group E'] [inner_product_space 𝕜 E] [inner_product_space 𝕜 E'] (f : E →ₗᵢ[𝕜] E') (p : submodule 𝕜 E) [complete_space p] (x : E) : f (orthogonal_projection p x) = orthogonal_projection (p.map f) (f x)
begin refine (eq_orthogonal_projection_of_mem_of_inner_eq_zero _ $ λ y hy, _).symm, refine submodule.apply_coe_mem_map _ _, rcases hy with ⟨x', hx', rfl : f x' = y⟩, rw [← f.map_sub, f.inner_map_map, orthogonal_projection_inner_eq_zero x x' hx'] end
lemma
linear_isometry.map_orthogonal_projection'
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "eq_orthogonal_projection_of_mem_of_inner_eq_zero", "inner_product_space", "normed_add_comm_group", "orthogonal_projection", "orthogonal_projection_inner_eq_zero", "submodule", "submodule.apply_coe_mem_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_map_apply {E E' : Type*} [normed_add_comm_group E] [normed_add_comm_group E'] [inner_product_space 𝕜 E] [inner_product_space 𝕜 E'] (f : E ≃ₗᵢ[𝕜] E') (p : submodule 𝕜 E) [complete_space p] (x : E') : (orthogonal_projection (p.map (f.to_linear_equiv : E →ₗ[𝕜] E')) x : E') = f (ortho...
by simpa only [f.coe_to_linear_isometry, f.apply_symm_apply] using (f.to_linear_isometry.map_orthogonal_projection p (f.symm x)).symm
lemma
orthogonal_projection_map_apply
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "inner_product_space", "normed_add_comm_group", "orthogonal_projection", "submodule" ]
Orthogonal projection onto the `submodule.map` of a subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_bot : orthogonal_projection (⊥ : submodule 𝕜 E) = 0
by ext
lemma
orthogonal_projection_bot
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "orthogonal_projection", "submodule" ]
The orthogonal projection onto the trivial submodule is the zero map.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_norm_le : ‖orthogonal_projection K‖ ≤ 1
linear_map.mk_continuous_norm_le _ (by norm_num) _
lemma
orthogonal_projection_norm_le
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "linear_map.mk_continuous_norm_le" ]
The orthogonal projection has norm `≤ 1`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_orthogonal_projection_singleton {v : E} (w : E) : (‖v‖ ^ 2 : 𝕜) • (orthogonal_projection (𝕜 ∙ v) w : E) = ⟪v, w⟫ • v
begin suffices : ↑(orthogonal_projection (𝕜 ∙ v) ((‖v‖ ^ 2 : 𝕜) • w)) = ⟪v, w⟫ • v, { simpa using this }, apply eq_orthogonal_projection_of_mem_of_inner_eq_zero, { rw submodule.mem_span_singleton, use ⟪v, w⟫ }, { intros x hx, obtain ⟨c, rfl⟩ := submodule.mem_span_singleton.mp hx, have hv : ↑‖v‖ ...
lemma
smul_orthogonal_projection_singleton
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "eq_orthogonal_projection_of_mem_of_inner_eq_zero", "inner_smul_left", "inner_smul_right", "inner_sub_left", "map_div₀", "mul_comm", "orthogonal_projection", "submodule.mem_span_singleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_singleton {v : E} (w : E) : (orthogonal_projection (𝕜 ∙ v) w : E) = (⟪v, w⟫ / ‖v‖ ^ 2) • v
begin by_cases hv : v = 0, { rw [hv, eq_orthogonal_projection_of_eq_submodule (submodule.span_zero_singleton 𝕜)], { simp }, { apply_instance } }, have hv' : ‖v‖ ≠ 0 := ne_of_gt (norm_pos_iff.mpr hv), have key : ((‖v‖ ^ 2 : 𝕜)⁻¹ * ‖v‖ ^ 2) • ↑(orthogonal_projection (𝕜 ∙ v) w) = ((‖v‖ ^ 2...
lemma
orthogonal_projection_singleton
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "eq_orthogonal_projection_of_eq_submodule", "orthogonal_projection", "smul_orthogonal_projection_singleton", "submodule.span_zero_singleton" ]
Formula for orthogonal projection onto a single vector.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_unit_singleton {v : E} (hv : ‖v‖ = 1) (w : E) : (orthogonal_projection (𝕜 ∙ v) w : E) = ⟪v, w⟫ • v
by { rw ← smul_orthogonal_projection_singleton 𝕜 w, simp [hv] }
lemma
orthogonal_projection_unit_singleton
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "orthogonal_projection", "smul_orthogonal_projection_singleton" ]
Formula for orthogonal projection onto a single unit vector.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_linear_equiv : E ≃ₗ[𝕜] E
linear_equiv.of_involutive (bit0 (K.subtype.comp (orthogonal_projection K).to_linear_map) - linear_map.id) (λ x, by simp [bit0])
def
reflection_linear_equiv
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "linear_equiv.of_involutive", "linear_map.id", "orthogonal_projection" ]
Auxiliary definition for `reflection`: the reflection as a linear equivalence.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection : E ≃ₗᵢ[𝕜] E
{ norm_map' := begin intros x, let w : K := orthogonal_projection K x, let v := x - w, have : ⟪v, w⟫ = 0 := orthogonal_projection_inner_eq_zero x w w.2, convert norm_sub_eq_norm_add this using 2, { rw [linear_equiv.coe_mk, reflection_linear_equiv, linear_equiv.to_fun_eq_coe, linear_equiv...
def
reflection
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "continuous_linear_map.coe_coe", "continuous_linear_map.to_linear_map_eq_coe", "linear_equiv.coe_mk", "linear_equiv.coe_of_involutive", "linear_equiv.to_fun_eq_coe", "linear_map.add_apply", "linear_map.comp_apply", "linear_map.id_apply", "linear_map.sub_apply", "norm_sub_eq_norm_add", "orthogona...
Reflection in a complete subspace of an inner product space. The word "reflection" is sometimes understood to mean specifically reflection in a codimension-one subspace, and sometimes more generally to cover operations such as reflection in a point. The definition here, of reflection in a subspace, is a more general ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_apply (p : E) : reflection K p = bit0 ↑(orthogonal_projection K p) - p
rfl
lemma
reflection_apply
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "orthogonal_projection", "reflection" ]
The result of reflecting.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_symm : (reflection K).symm = reflection K
rfl
lemma
reflection_symm
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "reflection" ]
Reflection is its own inverse.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_inv : (reflection K)⁻¹ = reflection K
rfl
lemma
reflection_inv
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "reflection" ]
Reflection is its own inverse.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_reflection (p : E) : reflection K (reflection K p) = p
(reflection K).left_inv p
lemma
reflection_reflection
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "reflection" ]
Reflecting twice in the same subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_involutive : function.involutive (reflection K)
reflection_reflection K
lemma
reflection_involutive
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "reflection", "reflection_reflection" ]
Reflection is involutive.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_trans_reflection : (reflection K).trans (reflection K) = linear_isometry_equiv.refl 𝕜 E
linear_isometry_equiv.ext $ reflection_involutive K
lemma
reflection_trans_reflection
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "linear_isometry_equiv.ext", "linear_isometry_equiv.refl", "reflection", "reflection_involutive" ]
Reflection is involutive.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_mul_reflection : reflection K * reflection K = 1
reflection_trans_reflection _
lemma
reflection_mul_reflection
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "reflection", "reflection_trans_reflection" ]
Reflection is involutive.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_eq_self_iff (x : E) : reflection K x = x ↔ x ∈ K
begin rw [←orthogonal_projection_eq_self_iff, reflection_apply, sub_eq_iff_eq_add', ← two_smul 𝕜, ← two_smul' 𝕜], refine (smul_right_injective E _).eq_iff, exact two_ne_zero end
lemma
reflection_eq_self_iff
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "reflection", "reflection_apply", "smul_right_injective", "two_ne_zero", "two_smul", "two_smul'" ]
A point is its own reflection if and only if it is in the subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_mem_subspace_eq_self {x : E} (hx : x ∈ K) : reflection K x = x
(reflection_eq_self_iff x).mpr hx
lemma
reflection_mem_subspace_eq_self
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "reflection", "reflection_eq_self_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_map_apply {E E' : Type*} [normed_add_comm_group E] [normed_add_comm_group E'] [inner_product_space 𝕜 E] [inner_product_space 𝕜 E'] (f : E ≃ₗᵢ[𝕜] E') (K : submodule 𝕜 E) [complete_space K] (x : E') : reflection (K.map (f.to_linear_equiv : E →ₗ[𝕜] E')) x = f (reflection K (f.symm x))
by simp [bit0, reflection_apply, orthogonal_projection_map_apply f K x]
lemma
reflection_map_apply
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "inner_product_space", "normed_add_comm_group", "orthogonal_projection_map_apply", "reflection", "reflection_apply", "submodule" ]
Reflection in the `submodule.map` of a subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_map {E E' : Type*} [normed_add_comm_group E] [normed_add_comm_group E'] [inner_product_space 𝕜 E] [inner_product_space 𝕜 E'] (f : E ≃ₗᵢ[𝕜] E') (K : submodule 𝕜 E) [complete_space K] : reflection (K.map (f.to_linear_equiv : E →ₗ[𝕜] E')) = f.symm.trans ((reflection K).trans f)
linear_isometry_equiv.ext $ reflection_map_apply f K
lemma
reflection_map
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "inner_product_space", "linear_isometry_equiv.ext", "normed_add_comm_group", "reflection", "reflection_map_apply", "submodule" ]
Reflection in the `submodule.map` of a subspace.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_bot : reflection (⊥ : submodule 𝕜 E) = linear_isometry_equiv.neg 𝕜
by ext; simp [reflection_apply]
lemma
reflection_bot
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "linear_isometry_equiv.neg", "reflection", "reflection_apply", "submodule" ]
Reflection through the trivial subspace {0} is just negation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submodule.sup_orthogonal_inf_of_complete_space {K₁ K₂ : submodule 𝕜 E} (h : K₁ ≤ K₂) [complete_space K₁] : K₁ ⊔ (K₁ᗮ ⊓ K₂) = K₂
begin ext x, rw submodule.mem_sup, let v : K₁ := orthogonal_projection K₁ x, have hvm : x - v ∈ K₁ᗮ := sub_orthogonal_projection_mem_orthogonal x, split, { rintro ⟨y, hy, z, hz, rfl⟩, exact K₂.add_mem (h hy) hz.2 }, { exact λ hx, ⟨v, v.prop, x - v, ⟨hvm, K₂.sub_mem hx (h v.prop)⟩, add_sub_cancel'_righ...
lemma
submodule.sup_orthogonal_inf_of_complete_space
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "orthogonal_projection", "sub_orthogonal_projection_mem_orthogonal", "submodule", "submodule.mem_sup" ]
If `K₁` is complete and contained in `K₂`, `K₁` and `K₁ᗮ ⊓ K₂` span `K₂`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submodule.sup_orthogonal_of_complete_space [complete_space K] : K ⊔ Kᗮ = ⊤
begin convert submodule.sup_orthogonal_inf_of_complete_space (le_top : K ≤ ⊤), simp end
lemma
submodule.sup_orthogonal_of_complete_space
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "le_top", "submodule.sup_orthogonal_inf_of_complete_space" ]
If `K` is complete, `K` and `Kᗮ` span the whole space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submodule.exists_sum_mem_mem_orthogonal [complete_space K] (v : E) : ∃ (y ∈ K) (z ∈ Kᗮ), v = y + z
begin have h_mem : v ∈ K ⊔ Kᗮ := by simp [submodule.sup_orthogonal_of_complete_space], obtain ⟨y, hy, z, hz, hyz⟩ := submodule.mem_sup.mp h_mem, exact ⟨y, hy, z, hz, hyz.symm⟩ end
lemma
submodule.exists_sum_mem_mem_orthogonal
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "submodule.sup_orthogonal_of_complete_space" ]
If `K` is complete, any `v` in `E` can be expressed as a sum of elements of `K` and `Kᗮ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submodule.orthogonal_orthogonal [complete_space K] : Kᗮᗮ = K
begin ext v, split, { obtain ⟨y, hy, z, hz, rfl⟩ := K.exists_sum_mem_mem_orthogonal v, intros hv, have hz' : z = 0, { have hyz : ⟪z, y⟫ = 0 := by simp [hz y hy, inner_eq_zero_symm], simpa [inner_add_right, hyz] using hv z hz }, simp [hy, hz'] }, { intros hv w hw, rw inner_eq_zero_symm,...
lemma
submodule.orthogonal_orthogonal
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "inner_add_right", "inner_eq_zero_symm" ]
If `K` is complete, then the orthogonal complement of its orthogonal complement is itself.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submodule.orthogonal_orthogonal_eq_closure [complete_space E] : Kᗮᗮ = K.topological_closure
begin refine le_antisymm _ _, { convert submodule.orthogonal_orthogonal_monotone K.le_topological_closure, haveI : complete_space K.topological_closure := K.is_closed_topological_closure.complete_space_coe, rw K.topological_closure.orthogonal_orthogonal }, { exact K.topological_closure_minimal K.le_...
lemma
submodule.orthogonal_orthogonal_eq_closure
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "submodule.orthogonal_orthogonal_monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submodule.is_compl_orthogonal_of_complete_space [complete_space K] : is_compl K Kᗮ
⟨K.orthogonal_disjoint, codisjoint_iff.2 submodule.sup_orthogonal_of_complete_space⟩
lemma
submodule.is_compl_orthogonal_of_complete_space
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "is_compl" ]
If `K` is complete, `K` and `Kᗮ` are complements of each other.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submodule.orthogonal_eq_bot_iff [complete_space (K : set E)] : Kᗮ = ⊥ ↔ K = ⊤
begin refine ⟨_, λ h, by rw [h, submodule.top_orthogonal_eq_bot] ⟩, intro h, have : K ⊔ Kᗮ = ⊤ := submodule.sup_orthogonal_of_complete_space, rwa [h, sup_comm, bot_sup_eq] at this, end
lemma
submodule.orthogonal_eq_bot_iff
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "bot_sup_eq", "complete_space", "submodule.sup_orthogonal_of_complete_space", "submodule.top_orthogonal_eq_bot", "sup_comm" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_orthogonal_projection_of_mem_orthogonal [complete_space K] {u v : E} (hv : v ∈ K) (hvo : u - v ∈ Kᗮ) : (orthogonal_projection K u : E) = v
eq_orthogonal_projection_fn_of_mem_of_inner_eq_zero hv (λ w, inner_eq_zero_symm.mp ∘ (hvo w))
lemma
eq_orthogonal_projection_of_mem_orthogonal
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "eq_orthogonal_projection_fn_of_mem_of_inner_eq_zero", "orthogonal_projection" ]
A point in `K` with the orthogonality property (here characterized in terms of `Kᗮ`) must be the orthogonal projection.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_orthogonal_projection_of_mem_orthogonal' [complete_space K] {u v z : E} (hv : v ∈ K) (hz : z ∈ Kᗮ) (hu : u = v + z) : (orthogonal_projection K u : E) = v
eq_orthogonal_projection_of_mem_orthogonal hv (by simpa [hu])
lemma
eq_orthogonal_projection_of_mem_orthogonal'
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "eq_orthogonal_projection_of_mem_orthogonal", "orthogonal_projection" ]
A point in `K` with the orthogonality property (here characterized in terms of `Kᗮ`) must be the orthogonal projection.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero [complete_space K] {v : E} (hv : v ∈ Kᗮ) : orthogonal_projection K v = 0
by { ext, convert eq_orthogonal_projection_of_mem_orthogonal _ _; simp [hv] }
lemma
orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "eq_orthogonal_projection_of_mem_orthogonal", "orthogonal_projection" ]
The orthogonal projection onto `K` of an element of `Kᗮ` is zero.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
submodule.is_ortho.orthogonal_projection_comp_subtypeL {U V : submodule 𝕜 E} [complete_space U] (h : U ⟂ V) : orthogonal_projection U ∘L V.subtypeL = 0
continuous_linear_map.ext $ λ v, orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero $ h.symm v.prop
lemma
submodule.is_ortho.orthogonal_projection_comp_subtypeL
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "continuous_linear_map.ext", "orthogonal_projection", "orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero", "submodule" ]
The projection into `U` from an orthogonal submodule `V` is the zero map.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_comp_subtypeL_eq_zero_iff {U V : submodule 𝕜 E} [complete_space U] : orthogonal_projection U ∘L V.subtypeL = 0 ↔ U ⟂ V
⟨λ h u hu v hv, begin convert orthogonal_projection_inner_eq_zero v u hu using 2, have : orthogonal_projection U v = 0 := fun_like.congr_fun h ⟨_, hv⟩, rw [this, submodule.coe_zero, sub_zero] end, submodule.is_ortho.orthogonal_projection_comp_subtypeL⟩
lemma
orthogonal_projection_comp_subtypeL_eq_zero_iff
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "fun_like.congr_fun", "orthogonal_projection", "orthogonal_projection_inner_eq_zero", "submodule", "submodule.coe_zero" ]
The projection into `U` from `V` is the zero map if and only if `U` and `V` are orthogonal.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_eq_linear_proj [complete_space K] (x : E) : orthogonal_projection K x = K.linear_proj_of_is_compl _ submodule.is_compl_orthogonal_of_complete_space x
begin have : is_compl K Kᗮ := submodule.is_compl_orthogonal_of_complete_space, nth_rewrite 0 [← submodule.linear_proj_add_linear_proj_of_is_compl_eq_self this x], rw [map_add, orthogonal_projection_mem_subspace_eq_self, orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero (submodule.coe_mem _), ...
lemma
orthogonal_projection_eq_linear_proj
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "is_compl", "orthogonal_projection", "orthogonal_projection_mem_subspace_eq_self", "orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero", "submodule.coe_mem", "submodule.is_compl_orthogonal_of_complete_space", "submodule.linear_proj_add_linear_proj_of_is_compl_eq_self" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_coe_linear_map_eq_linear_proj [complete_space K] : (orthogonal_projection K : E →ₗ[𝕜] K) = K.linear_proj_of_is_compl _ submodule.is_compl_orthogonal_of_complete_space
linear_map.ext $ orthogonal_projection_eq_linear_proj
lemma
orthogonal_projection_coe_linear_map_eq_linear_proj
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "linear_map.ext", "orthogonal_projection", "orthogonal_projection_eq_linear_proj", "submodule.is_compl_orthogonal_of_complete_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
reflection_mem_subspace_orthogonal_complement_eq_neg [complete_space K] {v : E} (hv : v ∈ Kᗮ) : reflection K v = - v
by simp [reflection_apply, orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero hv]
lemma
reflection_mem_subspace_orthogonal_complement_eq_neg
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero", "reflection", "reflection_apply" ]
The reflection in `K` of an element of `Kᗮ` is its negation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
orthogonal_projection_mem_subspace_orthogonal_precomplement_eq_zero [complete_space E] {v : E} (hv : v ∈ K) : orthogonal_projection Kᗮ v = 0
orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero (K.le_orthogonal_orthogonal hv)
lemma
orthogonal_projection_mem_subspace_orthogonal_precomplement_eq_zero
analysis.inner_product_space
src/analysis/inner_product_space/projection.lean
[ "algebra.direct_sum.decomposition", "analysis.convex.basic", "analysis.inner_product_space.orthogonal", "analysis.inner_product_space.symmetric", "analysis.normed_space.is_R_or_C", "data.is_R_or_C.lemmas" ]
[ "complete_space", "orthogonal_projection", "orthogonal_projection_mem_subspace_orthogonal_complement_eq_zero" ]
The orthogonal projection onto `Kᗮ` of an element of `K` is zero.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83