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B_mem_nhds_within_Ioi {K : set F} {r s ε x : ℝ} (hx : x ∈ B f K r s ε) : B f K r s ε ∈ 𝓝[>] x
begin obtain ⟨L, LK, hL₁, hL₂⟩ : ∃ (L : F), L ∈ K ∧ x ∈ A f L r ε ∧ x ∈ A f L s ε, by simpa only [B, mem_Union, mem_inter_iff, exists_prop] using hx, filter_upwards [A_mem_nhds_within_Ioi hL₁, A_mem_nhds_within_Ioi hL₂] with y hy₁ hy₂, simp only [B, mem_Union, mem_inter_iff, exists_prop], exact ⟨L, LK, hy₁,...
lemma
right_deriv_measurable_aux.B_mem_nhds_within_Ioi
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "exists_prop" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
measurable_set_B {K : set F} {r s ε : ℝ} : measurable_set (B f K r s ε)
measurable_set_of_mem_nhds_within_Ioi (λ x hx, B_mem_nhds_within_Ioi hx)
lemma
right_deriv_measurable_aux.measurable_set_B
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "measurable_set", "measurable_set_of_mem_nhds_within_Ioi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
A_mono (L : F) (r : ℝ) {ε δ : ℝ} (h : ε ≤ δ) : A f L r ε ⊆ A f L r δ
begin rintros x ⟨r', r'r, hr'⟩, refine ⟨r', r'r, λ y hy z hz, (hr' y hy z hz).trans (mul_le_mul_of_nonneg_right h _)⟩, linarith [hy.1, hy.2, r'r.2], end
lemma
right_deriv_measurable_aux.A_mono
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "mul_le_mul_of_nonneg_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_of_mem_A {r ε : ℝ} {L : F} {x : ℝ} (hx : x ∈ A f L r ε) {y z : ℝ} (hy : y ∈ Icc x (x + r/2)) (hz : z ∈ Icc x (x + r/2)) : ‖f z - f y - (z-y) • L‖ ≤ ε * r
begin rcases hx with ⟨r', r'mem, hr'⟩, have A : x + r / 2 ≤ x + r', by linarith [r'mem.1], exact hr' _ ((Icc_subset_Icc le_rfl A) hy) _ ((Icc_subset_Icc le_rfl A) hz), end
lemma
right_deriv_measurable_aux.le_of_mem_A
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "le_rfl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_A_of_differentiable {ε : ℝ} (hε : 0 < ε) {x : ℝ} (hx : differentiable_within_at ℝ f (Ici x) x) : ∃ R > 0, ∀ r ∈ Ioo (0 : ℝ) R, x ∈ A f (deriv_within f (Ici x) x) r ε
begin have := hx.has_deriv_within_at, simp_rw [has_deriv_within_at_iff_is_o, is_o_iff] at this, rcases mem_nhds_within_Ici_iff_exists_Ico_subset.1 (this (half_pos hε)) with ⟨m, xm, hm⟩, refine ⟨m - x, by linarith [show x < m, from xm], λ r hr, _⟩, have : r ∈ Ioc (r/2) r := ⟨half_lt_self hr.1, le_rfl⟩, refin...
lemma
right_deriv_measurable_aux.mem_A_of_differentiable
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "deriv_within", "differentiable_within_at", "half_pos", "has_deriv_within_at_iff_is_o", "mul_le_mul_of_nonneg_left", "real.norm_of_nonneg", "ring", "sub_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_sub_le_of_mem_A {r x : ℝ} (hr : 0 < r) (ε : ℝ) {L₁ L₂ : F} (h₁ : x ∈ A f L₁ r ε) (h₂ : x ∈ A f L₂ r ε) : ‖L₁ - L₂‖ ≤ 4 * ε
begin suffices H : ‖(r/2) • (L₁ - L₂)‖ ≤ (r / 2) * (4 * ε), by rwa [norm_smul, real.norm_of_nonneg (half_pos hr).le, mul_le_mul_left (half_pos hr)] at H, calc ‖(r/2) • (L₁ - L₂)‖ = ‖(f (x + r/2) - f x - (x + r/2 - x) • L₂) - (f (x + r/2) - f x - (x + r/2 - x) • L₁)‖ : by simp [smul_sub] ... ≤ ‖f (...
lemma
right_deriv_measurable_aux.norm_sub_le_of_mem_A
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "half_pos", "mul_le_mul_left", "norm_smul", "real.norm_of_nonneg", "ring", "smul_sub" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
differentiable_set_subset_D : {x | differentiable_within_at ℝ f (Ici x) x ∧ deriv_within f (Ici x) x ∈ K} ⊆ D f K
begin assume x hx, rw [D, mem_Inter], assume e, have : (0 : ℝ) < (1/2) ^ e := pow_pos (by norm_num) _, rcases mem_A_of_differentiable this hx.1 with ⟨R, R_pos, hR⟩, obtain ⟨n, hn⟩ : ∃ (n : ℕ), (1/2) ^ n < R := exists_pow_lt_of_lt_one R_pos (by norm_num : (1 : ℝ)/2 < 1), simp only [mem_Union, mem_Inter...
lemma
right_deriv_measurable_aux.differentiable_set_subset_D
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "deriv_within", "differentiable_within_at", "exists_pow_lt_of_lt_one", "pow_le_pow_of_le_one", "pow_pos" ]
Easy inclusion: a differentiability point with derivative in `K` belongs to `D f K`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
D_subset_differentiable_set {K : set F} (hK : is_complete K) : D f K ⊆ {x | differentiable_within_at ℝ f (Ici x) x ∧ deriv_within f (Ici x) x ∈ K}
begin have P : ∀ {n : ℕ}, (0 : ℝ) < (1/2) ^ n := pow_pos (by norm_num), assume x hx, have : ∀ (e : ℕ), ∃ (n : ℕ), ∀ p q, n ≤ p → n ≤ q → ∃ L ∈ K, x ∈ A f L ((1/2) ^ p) ((1/2) ^ e) ∩ A f L ((1/2) ^ q) ((1/2) ^ e), { assume e, have := mem_Inter.1 hx e, rcases mem_Union.1 this with ⟨n, hn⟩, refine ...
lemma
right_deriv_measurable_aux.D_subset_differentiable_set
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "Icc_mem_nhds_within_Ici", "cauchy_seq", "cauchy_seq_tendsto_of_is_complete", "deriv_within", "differentiable_within_at", "dist_comm", "div_nonneg", "div_pos", "eq_or_lt_of_le", "exists_nat_pow_near_of_lt_one", "exists_pow_lt_of_lt_one", "ge_iff_le", "has_deriv_within_at", "has_deriv_withi...
Harder inclusion: at a point in `D f K`, the function `f` has a derivative, in `K`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
differentiable_set_eq_D (hK : is_complete K) : {x | differentiable_within_at ℝ f (Ici x) x ∧ deriv_within f (Ici x) x ∈ K} = D f K
subset.antisymm (differentiable_set_subset_D _) (D_subset_differentiable_set hK)
theorem
right_deriv_measurable_aux.differentiable_set_eq_D
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "deriv_within", "differentiable_within_at", "is_complete" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
measurable_set_of_differentiable_within_at_Ici_of_is_complete {K : set F} (hK : is_complete K) : measurable_set {x | differentiable_within_at ℝ f (Ici x) x ∧ deriv_within f (Ici x) x ∈ K}
by simp [differentiable_set_eq_D K hK, D, measurable_set_B, measurable_set.Inter, measurable_set.Union]
theorem
measurable_set_of_differentiable_within_at_Ici_of_is_complete
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "deriv_within", "differentiable_within_at", "is_complete", "measurable_set", "measurable_set.Inter", "measurable_set.Union" ]
The set of right differentiability points of a function, with derivative in a given complete set, is Borel-measurable.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
measurable_set_of_differentiable_within_at_Ici : measurable_set {x | differentiable_within_at ℝ f (Ici x) x}
begin have : is_complete (univ : set F) := complete_univ, convert measurable_set_of_differentiable_within_at_Ici_of_is_complete f this, simp end
theorem
measurable_set_of_differentiable_within_at_Ici
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "complete_univ", "differentiable_within_at", "is_complete", "measurable_set", "measurable_set_of_differentiable_within_at_Ici_of_is_complete" ]
The set of right differentiability points of a function taking values in a complete space is Borel-measurable.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
measurable_deriv_within_Ici [measurable_space F] [borel_space F] : measurable (λ x, deriv_within f (Ici x) x)
begin refine measurable_of_is_closed (λ s hs, _), have : (λ x, deriv_within f (Ici x) x) ⁻¹' s = {x | differentiable_within_at ℝ f (Ici x) x ∧ deriv_within f (Ici x) x ∈ s} ∪ ({x | ¬differentiable_within_at ℝ f (Ici x) x} ∩ {x | (0 : F) ∈ s}) := set.ext (λ x, mem_preimage.trans deriv_within_mem_iff), ...
lemma
measurable_deriv_within_Ici
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "borel_space", "deriv_within", "deriv_within_mem_iff", "differentiable_within_at", "measurable", "measurable_of_is_closed", "measurable_set.const", "measurable_set_of_differentiable_within_at_Ici", "measurable_set_of_differentiable_within_at_Ici_of_is_complete", "measurable_space", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
strongly_measurable_deriv_within_Ici [second_countable_topology F] : strongly_measurable (λ x, deriv_within f (Ici x) x)
by { borelize F, exact (measurable_deriv_within_Ici f).strongly_measurable }
lemma
strongly_measurable_deriv_within_Ici
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "deriv_within", "measurable_deriv_within_Ici" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_measurable_deriv_within_Ici [measurable_space F] [borel_space F] (μ : measure ℝ) : ae_measurable (λ x, deriv_within f (Ici x) x) μ
(measurable_deriv_within_Ici f).ae_measurable
lemma
ae_measurable_deriv_within_Ici
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "ae_measurable", "borel_space", "deriv_within", "measurable_deriv_within_Ici", "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_strongly_measurable_deriv_within_Ici [second_countable_topology F] (μ : measure ℝ) : ae_strongly_measurable (λ x, deriv_within f (Ici x) x) μ
(strongly_measurable_deriv_within_Ici f).ae_strongly_measurable
lemma
ae_strongly_measurable_deriv_within_Ici
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "deriv_within", "strongly_measurable_deriv_within_Ici" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
measurable_set_of_differentiable_within_at_Ioi : measurable_set {x | differentiable_within_at ℝ f (Ioi x) x}
by simpa [differentiable_within_at_Ioi_iff_Ici] using measurable_set_of_differentiable_within_at_Ici f
theorem
measurable_set_of_differentiable_within_at_Ioi
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "differentiable_within_at", "differentiable_within_at_Ioi_iff_Ici", "measurable_set", "measurable_set_of_differentiable_within_at_Ici" ]
The set of right differentiability points of a function taking values in a complete space is Borel-measurable.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
measurable_deriv_within_Ioi [measurable_space F] [borel_space F] : measurable (λ x, deriv_within f (Ioi x) x)
by simpa [deriv_within_Ioi_eq_Ici] using measurable_deriv_within_Ici f
lemma
measurable_deriv_within_Ioi
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "borel_space", "deriv_within", "deriv_within_Ioi_eq_Ici", "measurable", "measurable_deriv_within_Ici", "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
strongly_measurable_deriv_within_Ioi [second_countable_topology F] : strongly_measurable (λ x, deriv_within f (Ioi x) x)
by { borelize F, exact (measurable_deriv_within_Ioi f).strongly_measurable }
lemma
strongly_measurable_deriv_within_Ioi
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "deriv_within", "measurable_deriv_within_Ioi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_measurable_deriv_within_Ioi [measurable_space F] [borel_space F] (μ : measure ℝ) : ae_measurable (λ x, deriv_within f (Ioi x) x) μ
(measurable_deriv_within_Ioi f).ae_measurable
lemma
ae_measurable_deriv_within_Ioi
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "ae_measurable", "borel_space", "deriv_within", "measurable_deriv_within_Ioi", "measurable_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ae_strongly_measurable_deriv_within_Ioi [second_countable_topology F] (μ : measure ℝ) : ae_strongly_measurable (λ x, deriv_within f (Ioi x) x) μ
(strongly_measurable_deriv_within_Ioi f).ae_strongly_measurable
lemma
ae_strongly_measurable_deriv_within_Ioi
analysis.calculus
src/analysis/calculus/fderiv_measurable.lean
[ "analysis.calculus.deriv.basic", "measure_theory.constructions.borel_space.continuous_linear_map", "measure_theory.function.strongly_measurable.basic" ]
[ "deriv_within", "strongly_measurable_deriv_within_Ioi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
convex.taylor_approx_two_segment {v w : E} (hv : x + v ∈ interior s) (hw : x + v + w ∈ interior s) : (λ h : ℝ, f (x + h • v + h • w) - f (x + h • v) - h • f' x w - h^2 • f'' v w - (h^2/2) • f'' w w) =o[𝓝[>] 0] (λ h, h^2)
begin -- it suffices to check that the expression is bounded by `ε * ((‖v‖ + ‖w‖) * ‖w‖) * h^2` for -- small enough `h`, for any positive `ε`. apply is_o.trans_is_O (is_o_iff.2 (λ ε εpos, _)) (is_O_const_mul_self ((‖v‖ + ‖w‖) * ‖w‖) _ _), -- consider a ball of radius `δ` around `x` in which the Taylor approxima...
lemma
convex.taylor_approx_two_segment
analysis.calculus
src/analysis/calculus/fderiv_symmetric.lean
[ "analysis.calculus.mean_value" ]
[ "abs_mul", "abs_of_nonneg", "abs_pow", "bit0_eq_zero", "continuous_const", "continuous_linear_map.add_apply", "continuous_linear_map.coe_smul'", "continuous_linear_map.coe_sub'", "continuous_linear_map.le_op_norm", "continuous_linear_map.map_add", "continuous_linear_map.map_smul", "continuous_...
Assume that `f` is differentiable inside a convex set `s`, and that its derivative `f'` is differentiable at a point `x`. Then, given two vectors `v` and `w` pointing inside `s`, one can Taylor-expand to order two the function `f` on the segment `[x + h v, x + h (v + w)]`, giving a bilinear estimate for `f (x + hv + hw...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
convex.is_o_alternate_sum_square {v w : E} (h4v : x + (4 : ℝ) • v ∈ interior s) (h4w : x + (4 : ℝ) • w ∈ interior s) : (λ h : ℝ, f (x + h • (2 • v + 2 • w)) + f (x + h • (v + w)) - f (x + h • (2 • v + w)) - f (x + h • (v + 2 • w)) - h^2 • f'' v w) =o[𝓝[>] 0] (λ h, h^2)
begin have A : (1 : ℝ)/2 ∈ Ioc (0 : ℝ) 1 := ⟨by norm_num, by norm_num⟩, have B : (1 : ℝ)/2 ∈ Icc (0 : ℝ) 1 := ⟨by norm_num, by norm_num⟩, have C : ∀ (w : E), (2 : ℝ) • w = 2 • w := λ w, by simp only [two_smul], have h2v2w : x + (2 : ℝ) • v + (2 : ℝ) • w ∈ interior s, { convert s_conv.interior.add_smul_sub_mem...
lemma
convex.is_o_alternate_sum_square
analysis.calculus
src/analysis/calculus/fderiv_symmetric.lean
[ "analysis.calculus.mean_value" ]
[ "add_smul", "bit0_eq_zero", "continuous_linear_map.add_apply", "continuous_linear_map.coe_smul'", "continuous_linear_map.map_add", "continuous_linear_map.map_smul", "interior", "inv_smul_smul₀", "one_div", "one_ne_zero", "pi.smul_apply", "smul_add", "smul_smul", "smul_sub", "two_smul" ]
One can get `f'' v w` as the limit of `h ^ (-2)` times the alternate sum of the values of `f` along the vertices of a quadrilateral with sides `h v` and `h w` based at `x`. In a setting where `f` is not guaranteed to be continuous at `f`, we can still get this if we use a quadrilateral based at `h v + h w`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
convex.second_derivative_within_at_symmetric_of_mem_interior {v w : E} (h4v : x + (4 : ℝ) • v ∈ interior s) (h4w : x + (4 : ℝ) • w ∈ interior s) : f'' w v = f'' v w
begin have A : (λ h : ℝ, h^2 • (f'' w v- f'' v w)) =o[𝓝[>] 0] (λ h, h^2), { convert (s_conv.is_o_alternate_sum_square hf xs hx h4v h4w).sub (s_conv.is_o_alternate_sum_square hf xs hx h4w h4v), ext h, simp only [add_comm, smul_add, smul_sub], abel }, have B : (λ h : ℝ, f'' w v - f'' v w) =...
lemma
convex.second_derivative_within_at_symmetric_of_mem_interior
analysis.calculus
src/analysis/calculus/fderiv_symmetric.lean
[ "analysis.calculus.mean_value" ]
[ "has_lt.lt.ne'", "interior", "one_smul", "self_mem_nhds_within", "smul_add", "smul_smul", "smul_sub" ]
Assume that `f` is differentiable inside a convex set `s`, and that its derivative `f'` is differentiable at a point `x`. Then, given two vectors `v` and `w` pointing inside `s`, one has `f'' v w = f'' w v`. Superseded by `convex.second_derivative_within_at_symmetric`, which removes the assumption that `v` and `w` poin...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
convex.second_derivative_within_at_symmetric {s : set E} (s_conv : convex ℝ s) (hne : (interior s).nonempty) {f : E → F} {f' : E → (E →L[ℝ] F)} {f'' : E →L[ℝ] (E →L[ℝ] F)} (hf : ∀ x ∈ interior s, has_fderiv_at f (f' x) x) {x : E} (xs : x ∈ s) (hx : has_fderiv_within_at f' f'' (interior s) x) (v w : E) : f'' v...
begin /- we work around a point `x + 4 z` in the interior of `s`. For any vector `m`, then `x + 4 (z + t m)` also belongs to the interior of `s` for small enough `t`. This means that we will be able to apply `second_derivative_within_at_symmetric_of_mem_interior` to show that `f''` is symmetric, after cancellin...
theorem
convex.second_derivative_within_at_symmetric
analysis.calculus
src/analysis/calculus/fderiv_symmetric.lean
[ "analysis.calculus.mean_value" ]
[ "continuous_at_const", "continuous_linear_map.add_apply", "continuous_linear_map.coe_smul'", "continuous_linear_map.map_add", "continuous_linear_map.map_smul", "continuous_linear_map.map_zero", "continuous_linear_map.zero_apply", "convex", "filter.tendsto", "has_fderiv_at", "has_fderiv_within_at...
If a function is differentiable inside a convex set with nonempty interior, and has a second derivative at a point of this convex set, then this second derivative is symmetric.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
second_derivative_symmetric_of_eventually {f : E → F} {f' : E → (E →L[ℝ] F)} {f'' : E →L[ℝ] (E →L[ℝ] F)} (hf : ∀ᶠ y in 𝓝 x, has_fderiv_at f (f' y) y) (hx : has_fderiv_at f' f'' x) (v w : E) : f'' v w = f'' w v
begin rcases metric.mem_nhds_iff.1 hf with ⟨ε, εpos, hε⟩, have A : (interior (metric.ball x ε)).nonempty, by rwa [metric.is_open_ball.interior_eq, metric.nonempty_ball], exact convex.second_derivative_within_at_symmetric (convex_ball x ε) A (λ y hy, hε (interior_subset hy)) (metric.mem_ball_self εpos) hx....
theorem
second_derivative_symmetric_of_eventually
analysis.calculus
src/analysis/calculus/fderiv_symmetric.lean
[ "analysis.calculus.mean_value" ]
[ "convex.second_derivative_within_at_symmetric", "convex_ball", "has_fderiv_at", "interior", "interior_subset", "metric.ball", "metric.mem_ball_self", "metric.nonempty_ball" ]
If a function is differentiable around `x`, and has two derivatives at `x`, then the second derivative is symmetric.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
second_derivative_symmetric {f : E → F} {f' : E → (E →L[ℝ] F)} {f'' : E →L[ℝ] (E →L[ℝ] F)} (hf : ∀ y, has_fderiv_at f (f' y) y) (hx : has_fderiv_at f' f'' x) (v w : E) : f'' v w = f'' w v
second_derivative_symmetric_of_eventually (filter.eventually_of_forall hf) hx v w
theorem
second_derivative_symmetric
analysis.calculus
src/analysis/calculus/fderiv_symmetric.lean
[ "analysis.calculus.mean_value" ]
[ "filter.eventually_of_forall", "has_fderiv_at", "second_derivative_symmetric_of_eventually" ]
If a function is differentiable, and has two derivatives at `x`, then the second derivative is symmetric.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
formal_multilinear_series (𝕜 : Type*) (E : Type*) (F : Type*) [ring 𝕜] [add_comm_group E] [module 𝕜 E] [topological_space E] [topological_add_group E] [has_continuous_const_smul 𝕜 E] [add_comm_group F] [module 𝕜 F] [topological_space F] [topological_add_group F] [has_continuous_const_smul 𝕜 F]
Π (n : ℕ), (E [×n]→L[𝕜] F)
def
formal_multilinear_series
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "add_comm_group", "has_continuous_const_smul", "module", "ring", "topological_add_group", "topological_space" ]
A formal multilinear series over a field `𝕜`, from `E` to `F`, is given by a family of multilinear maps from `E^n` to `F` for all `n`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ext_iff {p q : formal_multilinear_series 𝕜 E F} : p = q ↔ ∀ n, p n = q n
function.funext_iff
lemma
formal_multilinear_series.ext_iff
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series", "function.funext_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ne_iff {p q : formal_multilinear_series 𝕜 E F} : p ≠ q ↔ ∃ n, p n ≠ q n
function.ne_iff
lemma
formal_multilinear_series.ne_iff
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series", "function.ne_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
remove_zero (p : formal_multilinear_series 𝕜 E F) : formal_multilinear_series 𝕜 E F
| 0 := 0 | (n + 1) := p (n + 1)
def
formal_multilinear_series.remove_zero
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
Killing the zeroth coefficient in a formal multilinear series
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
remove_zero_coeff_zero (p : formal_multilinear_series 𝕜 E F) : p.remove_zero 0 = 0
rfl
lemma
formal_multilinear_series.remove_zero_coeff_zero
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
remove_zero_coeff_succ (p : formal_multilinear_series 𝕜 E F) (n : ℕ) : p.remove_zero (n+1) = p (n+1)
rfl
lemma
formal_multilinear_series.remove_zero_coeff_succ
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
remove_zero_of_pos (p : formal_multilinear_series 𝕜 E F) {n : ℕ} (h : 0 < n) : p.remove_zero n = p n
by { rw ← nat.succ_pred_eq_of_pos h, refl }
lemma
formal_multilinear_series.remove_zero_of_pos
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
congr (p : formal_multilinear_series 𝕜 E F) {m n : ℕ} {v : fin m → E} {w : fin n → E} (h1 : m = n) (h2 : ∀ (i : ℕ) (him : i < m) (hin : i < n), v ⟨i, him⟩ = w ⟨i, hin⟩) : p m v = p n w
by { cases h1, congr' with ⟨i, hi⟩, exact h2 i hi hi }
lemma
formal_multilinear_series.congr
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
Convenience congruence lemma stating in a dependent setting that, if the arguments to a formal multilinear series are equal, then the values are also equal.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_continuous_linear_map (p : formal_multilinear_series 𝕜 F G) (u : E →L[𝕜] F) : formal_multilinear_series 𝕜 E G
λ n, (p n).comp_continuous_linear_map (λ (i : fin n), u)
def
formal_multilinear_series.comp_continuous_linear_map
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
Composing each term `pₙ` in a formal multilinear series with `(u, ..., u)` where `u` is a fixed continuous linear map, gives a new formal multilinear series `p.comp_continuous_linear_map u`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_continuous_linear_map_apply (p : formal_multilinear_series 𝕜 F G) (u : E →L[𝕜] F) (n : ℕ) (v : fin n → E) : (p.comp_continuous_linear_map u) n v = p n (u ∘ v)
rfl
lemma
formal_multilinear_series.comp_continuous_linear_map_apply
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars (p : formal_multilinear_series 𝕜' E F) : formal_multilinear_series 𝕜 E F
λ n, (p n).restrict_scalars 𝕜
def
formal_multilinear_series.restrict_scalars
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series", "restrict_scalars" ]
Reinterpret a formal `𝕜'`-multilinear series as a formal `𝕜`-multilinear series.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
shift : formal_multilinear_series 𝕜 E (E →L[𝕜] F)
λn, (p n.succ).curry_right
def
formal_multilinear_series.shift
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
Forgetting the zeroth term in a formal multilinear series, and interpreting the following terms as multilinear maps into `E →L[𝕜] F`. If `p` corresponds to the Taylor series of a function, then `p.shift` is the Taylor series of the derivative of the function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unshift (q : formal_multilinear_series 𝕜 E (E →L[𝕜] F)) (z : F) : formal_multilinear_series 𝕜 E F
| 0 := (continuous_multilinear_curry_fin0 𝕜 E F).symm z | (n + 1) := continuous_multilinear_curry_right_equiv' 𝕜 n E F (q n)
def
formal_multilinear_series.unshift
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "continuous_multilinear_curry_fin0", "continuous_multilinear_curry_right_equiv'", "formal_multilinear_series" ]
Adding a zeroth term to a formal multilinear series taking values in `E →L[𝕜] F`. This corresponds to starting from a Taylor series for the derivative of a function, and building a Taylor series for the function itself.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_formal_multilinear_series (f : F →L[𝕜] G) (p : formal_multilinear_series 𝕜 E F) : formal_multilinear_series 𝕜 E G
λ n, f.comp_continuous_multilinear_map (p n)
def
continuous_linear_map.comp_formal_multilinear_series
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
Composing each term `pₙ` in a formal multilinear series with a continuous linear map `f` on the left gives a new formal multilinear series `f.comp_formal_multilinear_series p` whose general term is `f ∘ pₙ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_formal_multilinear_series_apply (f : F →L[𝕜] G) (p : formal_multilinear_series 𝕜 E F) (n : ℕ) : (f.comp_formal_multilinear_series p) n = f.comp_continuous_multilinear_map (p n)
rfl
lemma
continuous_linear_map.comp_formal_multilinear_series_apply
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_formal_multilinear_series_apply' (f : F →L[𝕜] G) (p : formal_multilinear_series 𝕜 E F) (n : ℕ) (v : fin n → E) : (f.comp_formal_multilinear_series p) n v = f (p n v)
rfl
lemma
continuous_linear_map.comp_formal_multilinear_series_apply'
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
order (p : formal_multilinear_series 𝕜 E F) : ℕ
Inf { n | p n ≠ 0 }
def
formal_multilinear_series.order
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
The index of the first non-zero coefficient in `p` (or `0` if all coefficients are zero). This is the order of the isolated zero of an analytic function `f` at a point if `p` is the Taylor series of `f` at that point.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
order_zero : (0 : formal_multilinear_series 𝕜 E F).order = 0
by simp [order]
lemma
formal_multilinear_series.order_zero
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ne_zero_of_order_ne_zero (hp : p.order ≠ 0) : p ≠ 0
λ h, by simpa [h] using hp
lemma
formal_multilinear_series.ne_zero_of_order_ne_zero
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
order_eq_find [decidable_pred (λ n, p n ≠ 0)] (hp : ∃ n, p n ≠ 0) : p.order = nat.find hp
by simp [order, Inf, hp]
lemma
formal_multilinear_series.order_eq_find
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
order_eq_find' [decidable_pred (λ n, p n ≠ 0)] (hp : p ≠ 0) : p.order = nat.find (formal_multilinear_series.ne_iff.mp hp)
order_eq_find _
lemma
formal_multilinear_series.order_eq_find'
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
order_eq_zero_iff (hp : p ≠ 0) : p.order = 0 ↔ p 0 ≠ 0
begin classical, have : ∃ n, p n ≠ 0 := formal_multilinear_series.ne_iff.mp hp, simp [order_eq_find this, hp] end
lemma
formal_multilinear_series.order_eq_zero_iff
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
order_eq_zero_iff' : p.order = 0 ↔ p = 0 ∨ p 0 ≠ 0
by { by_cases h : p = 0; simp [h, order_eq_zero_iff] }
lemma
formal_multilinear_series.order_eq_zero_iff'
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_order_ne_zero (hp : p ≠ 0) : p p.order ≠ 0
begin classical, let h := formal_multilinear_series.ne_iff.mp hp, exact (order_eq_find h).symm ▸ nat.find_spec h end
lemma
formal_multilinear_series.apply_order_ne_zero
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_order_ne_zero' (hp : p.order ≠ 0) : p p.order ≠ 0
apply_order_ne_zero (ne_zero_of_order_ne_zero hp)
lemma
formal_multilinear_series.apply_order_ne_zero'
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_eq_zero_of_lt_order (hp : n < p.order) : p n = 0
begin by_cases p = 0, { simp [h] }, { classical, rw [order_eq_find' h] at hp, simpa using nat.find_min _ hp } end
lemma
formal_multilinear_series.apply_eq_zero_of_lt_order
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coeff (p : formal_multilinear_series 𝕜 𝕜 E) (n : ℕ) : E
p n 1
def
formal_multilinear_series.coeff
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
The `n`th coefficient of `p` when seen as a power series.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_pi_field_coeff_eq (p : formal_multilinear_series 𝕜 𝕜 E) (n : ℕ) : continuous_multilinear_map.mk_pi_field 𝕜 (fin n) (p.coeff n) = p n
(p n).mk_pi_field_apply_one_eq_self
lemma
formal_multilinear_series.mk_pi_field_coeff_eq
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "continuous_multilinear_map.mk_pi_field", "formal_multilinear_series" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_eq_prod_smul_coeff : p n y = (∏ i, y i) • p.coeff n
begin convert (p n).to_multilinear_map.map_smul_univ y 1, funext; simp only [pi.one_apply, algebra.id.smul_eq_mul, mul_one], end
lemma
formal_multilinear_series.apply_eq_prod_smul_coeff
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "algebra.id.smul_eq_mul", "mul_one", "pi.one_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coeff_eq_zero : p.coeff n = 0 ↔ p n = 0
by rw [← mk_pi_field_coeff_eq p, continuous_multilinear_map.mk_pi_field_eq_zero_iff]
lemma
formal_multilinear_series.coeff_eq_zero
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "continuous_multilinear_map.mk_pi_field_eq_zero_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_eq_pow_smul_coeff : p n (λ _, z) = z ^ n • p.coeff n
by simp
lemma
formal_multilinear_series.apply_eq_pow_smul_coeff
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_apply_eq_norm_coef : ‖p n‖ = ‖coeff p n‖
by rw [← mk_pi_field_coeff_eq p, continuous_multilinear_map.norm_mk_pi_field]
lemma
formal_multilinear_series.norm_apply_eq_norm_coef
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "continuous_multilinear_map.norm_mk_pi_field" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fslope (p : formal_multilinear_series 𝕜 𝕜 E) : formal_multilinear_series 𝕜 𝕜 E
λ n, (p (n + 1)).curry_left 1
def
formal_multilinear_series.fslope
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "formal_multilinear_series" ]
The formal counterpart of `dslope`, corresponding to the expansion of `(f z - f 0) / z`. If `f` has `p` as a power series, then `dslope f` has `fslope p` as a power series.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coeff_fslope : p.fslope.coeff n = p.coeff (n + 1)
begin have : @fin.cons n (λ _, 𝕜) 1 (1 : fin n → 𝕜) = 1 := fin.cons_self_tail 1, simp only [fslope, coeff, continuous_multilinear_map.curry_left_apply, this], end
lemma
formal_multilinear_series.coeff_fslope
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "continuous_multilinear_map.curry_left_apply", "fin.cons", "fin.cons_self_tail" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coeff_iterate_fslope (k n : ℕ) : (fslope^[k] p).coeff n = p.coeff (n + k)
by induction k with k ih generalizing p; refl <|> simpa [ih]
lemma
formal_multilinear_series.coeff_iterate_fslope
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "ih" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const_formal_multilinear_series (𝕜 : Type*) [nontrivially_normed_field 𝕜] (E : Type*) [normed_add_comm_group E] [normed_space 𝕜 E] [has_continuous_const_smul 𝕜 E] [topological_add_group E] {F : Type*} [normed_add_comm_group F] [topological_add_group F] [normed_space 𝕜 F] [has_continuous_const_smul 𝕜 F] (c ...
| 0 := continuous_multilinear_map.curry0 _ _ c | _ := 0
def
const_formal_multilinear_series
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "continuous_multilinear_map.curry0", "formal_multilinear_series", "has_continuous_const_smul", "nontrivially_normed_field", "normed_add_comm_group", "normed_space", "topological_add_group" ]
The formal multilinear series where all terms of positive degree are equal to zero, and the term of degree zero is `c`. It is the power series expansion of the constant function equal to `c` everywhere.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
const_formal_multilinear_series_apply [nontrivially_normed_field 𝕜] [normed_add_comm_group E] [normed_add_comm_group F] [normed_space 𝕜 E] [normed_space 𝕜 F] {c : F} {n : ℕ} (hn : n ≠ 0) : const_formal_multilinear_series 𝕜 E c n = 0
nat.cases_on n (λ hn, (hn rfl).elim) (λ _ _, rfl) hn
lemma
const_formal_multilinear_series_apply
analysis.calculus
src/analysis/calculus/formal_multilinear_series.lean
[ "analysis.normed_space.multilinear" ]
[ "const_formal_multilinear_series", "nontrivially_normed_field", "normed_add_comm_group", "normed_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_function_data (𝕜 : Type*) [nontrivially_normed_field 𝕜] (E : Type*) [normed_add_comm_group E] [normed_space 𝕜 E] [complete_space E] (F : Type*) [normed_add_comm_group F] [normed_space 𝕜 F] [complete_space F] (G : Type*) [normed_add_comm_group G] [normed_space 𝕜 G] [complete_space G]
(left_fun : E → F) (left_deriv : E →L[𝕜] F) (right_fun : E → G) (right_deriv : E →L[𝕜] G) (pt : E) (left_has_deriv : has_strict_fderiv_at left_fun left_deriv pt) (right_has_deriv : has_strict_fderiv_at right_fun right_deriv pt) (left_range : range left_deriv = ⊤) (right_range : range right_deriv = ⊤) (is_compl_ker : ...
structure
implicit_function_data
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "complete_space", "has_strict_fderiv_at", "is_compl", "nontrivially_normed_field", "normed_add_comm_group", "normed_space" ]
Data for the general version of the implicit function theorem. It holds two functions `f : E → F` and `g : E → G` (named `left_fun` and `right_fun`) and a point `a` (named `pt`) such that * both functions are strictly differentiable at `a`; * the derivatives are surjective; * the kernels of the derivatives are complem...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_fun (x : E) : F × G
(φ.left_fun x, φ.right_fun x)
def
implicit_function_data.prod_fun
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
The function given by `x ↦ (left_fun x, right_fun x)`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_fun_apply (x : E) : φ.prod_fun x = (φ.left_fun x, φ.right_fun x)
rfl
lemma
implicit_function_data.prod_fun_apply
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_strict_fderiv_at : has_strict_fderiv_at φ.prod_fun (φ.left_deriv.equiv_prod_of_surjective_of_is_compl φ.right_deriv φ.left_range φ.right_range φ.is_compl_ker : E →L[𝕜] F × G) φ.pt
φ.left_has_deriv.prod φ.right_has_deriv
lemma
implicit_function_data.has_strict_fderiv_at
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_local_homeomorph : local_homeomorph E (F × G)
φ.has_strict_fderiv_at.to_local_homeomorph _
def
implicit_function_data.to_local_homeomorph
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "local_homeomorph" ]
Implicit function theorem. If `f : E → F` and `g : E → G` are two maps strictly differentiable at `a`, their derivatives `f'`, `g'` are surjective, and the kernels of these derivatives are complementary subspaces of `E`, then `x ↦ (f x, g x)` defines a local homeomorphism between `E` and `F × G`. In particular, `{x | f...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_function : F → G → E
function.curry $ φ.to_local_homeomorph.symm
def
implicit_function_data.implicit_function
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
Implicit function theorem. If `f : E → F` and `g : E → G` are two maps strictly differentiable at `a`, their derivatives `f'`, `g'` are surjective, and the kernels of these derivatives are complementary subspaces of `E`, then `implicit_function_of_is_compl_ker` is the unique (germ of a) map `φ : F → G → E` such that `f...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_local_homeomorph_coe : ⇑(φ.to_local_homeomorph) = φ.prod_fun
rfl
lemma
implicit_function_data.to_local_homeomorph_coe
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_local_homeomorph_apply (x : E) : φ.to_local_homeomorph x = (φ.left_fun x, φ.right_fun x)
rfl
lemma
implicit_function_data.to_local_homeomorph_apply
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
pt_mem_to_local_homeomorph_source : φ.pt ∈ φ.to_local_homeomorph.source
φ.has_strict_fderiv_at.mem_to_local_homeomorph_source
lemma
implicit_function_data.pt_mem_to_local_homeomorph_source
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_pt_mem_to_local_homeomorph_target : (φ.left_fun φ.pt, φ.right_fun φ.pt) ∈ φ.to_local_homeomorph.target
φ.to_local_homeomorph.map_source $ φ.pt_mem_to_local_homeomorph_source
lemma
implicit_function_data.map_pt_mem_to_local_homeomorph_target
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
prod_map_implicit_function : ∀ᶠ (p : F × G) in 𝓝 (φ.prod_fun φ.pt), φ.prod_fun (φ.implicit_function p.1 p.2) = p
φ.has_strict_fderiv_at.eventually_right_inverse.mono $ λ ⟨z, y⟩ h, h
lemma
implicit_function_data.prod_map_implicit_function
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_map_implicit_function : ∀ᶠ (p : F × G) in 𝓝 (φ.prod_fun φ.pt), φ.left_fun (φ.implicit_function p.1 p.2) = p.1
φ.prod_map_implicit_function.mono $ λ z, congr_arg prod.fst
lemma
implicit_function_data.left_map_implicit_function
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_map_implicit_function : ∀ᶠ (p : F × G) in 𝓝 (φ.prod_fun φ.pt), φ.right_fun (φ.implicit_function p.1 p.2) = p.2
φ.prod_map_implicit_function.mono $ λ z, congr_arg prod.snd
lemma
implicit_function_data.right_map_implicit_function
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_function_apply_image : ∀ᶠ x in 𝓝 φ.pt, φ.implicit_function (φ.left_fun x) (φ.right_fun x) = x
φ.has_strict_fderiv_at.eventually_left_inverse
lemma
implicit_function_data.implicit_function_apply_image
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_nhds_eq : map φ.left_fun (𝓝 φ.pt) = 𝓝 (φ.left_fun φ.pt)
show map (prod.fst ∘ φ.prod_fun) (𝓝 φ.pt) = 𝓝 (φ.prod_fun φ.pt).1, by rw [← map_map, φ.has_strict_fderiv_at.map_nhds_eq_of_equiv, map_fst_nhds]
lemma
implicit_function_data.map_nhds_eq
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "map_fst_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_function_has_strict_fderiv_at (g'inv : G →L[𝕜] E) (hg'inv : φ.right_deriv.comp g'inv = continuous_linear_map.id 𝕜 G) (hg'invf : φ.left_deriv.comp g'inv = 0) : has_strict_fderiv_at (φ.implicit_function (φ.left_fun φ.pt)) g'inv (φ.right_fun φ.pt)
begin have := φ.has_strict_fderiv_at.to_local_inverse, simp only [prod_fun] at this, convert this.comp (φ.right_fun φ.pt) ((has_strict_fderiv_at_const _ _).prod (has_strict_fderiv_at_id _)), simp only [continuous_linear_map.ext_iff, continuous_linear_map.coe_comp', function.comp_app] at hg'inv hg'invf ⊢...
lemma
implicit_function_data.implicit_function_has_strict_fderiv_at
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "continuous_linear_equiv.eq_symm_apply", "continuous_linear_map.coe_comp'", "continuous_linear_map.ext_iff", "continuous_linear_map.id", "has_strict_fderiv_at", "has_strict_fderiv_at_const", "has_strict_fderiv_at_id" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_function_data_of_complemented (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : implicit_function_data 𝕜 E F (ker f')
{ left_fun := f, left_deriv := f', right_fun := λ x, classical.some hker (x - a), right_deriv := classical.some hker, pt := a, left_has_deriv := hf, right_has_deriv := (classical.some hker).has_strict_fderiv_at.comp a ((has_strict_fderiv_at_id a).sub_const a), left_range := hf', right_range := linea...
def
has_strict_fderiv_at.implicit_function_data_of_complemented
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at", "has_strict_fderiv_at.comp", "has_strict_fderiv_at_id", "implicit_function_data", "linear_map.is_compl_of_proj", "linear_map.range_eq_of_proj" ]
Data used to apply the generic implicit function theorem to the case of a strictly differentiable map such that its derivative is surjective and has a complemented kernel.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph_of_complemented (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : local_homeomorph E (F × (ker f'))
(implicit_function_data_of_complemented f f' hf hf' hker).to_local_homeomorph
def
has_strict_fderiv_at.implicit_to_local_homeomorph_of_complemented
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at", "local_homeomorph" ]
A local homeomorphism between `E` and `F × f'.ker` sending level surfaces of `f` to vertical subspaces.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_function_of_complemented (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : F → (ker f') → E
(implicit_function_data_of_complemented f f' hf hf' hker).implicit_function
def
has_strict_fderiv_at.implicit_function_of_complemented
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
Implicit function `g` defined by `f (g z y) = z`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph_of_complemented_fst (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) (x : E) : (hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker x).fst = f x
rfl
lemma
has_strict_fderiv_at.implicit_to_local_homeomorph_of_complemented_fst
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph_of_complemented_apply (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) (y : E) : hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker y = (f y, classical.some hker (y - a))
rfl
lemma
has_strict_fderiv_at.implicit_to_local_homeomorph_of_complemented_apply
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph_of_complemented_apply_ker (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) (y : ker f') : hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker (y + a) = (f (y + a), y)
by simp only [implicit_to_local_homeomorph_of_complemented_apply, add_sub_cancel, classical.some_spec hker]
lemma
has_strict_fderiv_at.implicit_to_local_homeomorph_of_complemented_apply_ker
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph_of_complemented_self (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker a = (f a, 0)
by simp [hf.implicit_to_local_homeomorph_of_complemented_apply]
lemma
has_strict_fderiv_at.implicit_to_local_homeomorph_of_complemented_self
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_implicit_to_local_homeomorph_of_complemented_source (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : a ∈ (hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker).source
mem_to_local_homeomorph_source _
lemma
has_strict_fderiv_at.mem_implicit_to_local_homeomorph_of_complemented_source
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_implicit_to_local_homeomorph_of_complemented_target (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : (f a, (0 : ker f')) ∈ (hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker).target
by simpa only [implicit_to_local_homeomorph_of_complemented_self] using ((hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker).map_source $ (hf.mem_implicit_to_local_homeomorph_of_complemented_source hf' hker))
lemma
has_strict_fderiv_at.mem_implicit_to_local_homeomorph_of_complemented_target
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_implicit_function_of_complemented_eq (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : ∀ᶠ (p : F × (ker f')) in 𝓝 (f a, 0), f (hf.implicit_function_of_complemented f f' hf' hker p.1 p.2) = p.1
((hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker).eventually_right_inverse $ hf.mem_implicit_to_local_homeomorph_of_complemented_target hf' hker).mono $ λ ⟨z, y⟩ h, congr_arg prod.fst h
lemma
has_strict_fderiv_at.map_implicit_function_of_complemented_eq
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
`implicit_function_of_complemented` sends `(z, y)` to a point in `f ⁻¹' z`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_implicit_function_of_complemented (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : ∀ᶠ x in 𝓝 a, hf.implicit_function_of_complemented f f' hf' hker (f x) (hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker x).snd = x
(implicit_function_data_of_complemented f f' hf hf' hker).implicit_function_apply_image
lemma
has_strict_fderiv_at.eq_implicit_function_of_complemented
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
Any point in some neighborhood of `a` can be represented as `implicit_function` of some point.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_function_of_complemented_apply_image (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : hf.implicit_function_of_complemented f f' hf' hker (f a) 0 = a
begin convert (hf.implicit_to_local_homeomorph_of_complemented f f' hf' hker).left_inv (hf.mem_implicit_to_local_homeomorph_of_complemented_source hf' hker), exact congr_arg prod.snd (hf.implicit_to_local_homeomorph_of_complemented_self hf' hker).symm end
lemma
has_strict_fderiv_at.implicit_function_of_complemented_apply_image
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_implicit_function_of_complemented (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (hker : (ker f').closed_complemented) : has_strict_fderiv_at (hf.implicit_function_of_complemented f f' hf' hker (f a)) (ker f').subtypeL 0
begin convert (implicit_function_data_of_complemented f f' hf hf' hker).implicit_function_has_strict_fderiv_at (ker f').subtypeL _ _, swap, { ext, simp only [classical.some_spec hker, implicit_function_data_of_complemented, continuous_linear_map.coe_comp', submodule.coe_subtypeL', submodul...
lemma
has_strict_fderiv_at.to_implicit_function_of_complemented
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "continuous_linear_map.coe_comp'", "continuous_linear_map.coe_id'", "continuous_linear_map.zero_apply", "has_strict_fderiv_at", "linear_map.map_coe_ker", "submodule.coe_subtype", "submodule.coe_subtypeL'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) : local_homeomorph E (F × (ker f'))
by haveI := finite_dimensional.complete 𝕜 F; exact hf.implicit_to_local_homeomorph_of_complemented f f' hf' f'.ker_closed_complemented_of_finite_dimensional_range
def
has_strict_fderiv_at.implicit_to_local_homeomorph
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "finite_dimensional.complete", "has_strict_fderiv_at", "local_homeomorph" ]
Given a map `f : E → F` to a finite dimensional space with a surjective derivative `f'`, returns a local homeomorphism between `E` and `F × ker f'`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_function (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) : F → (ker f') → E
function.curry $ (hf.implicit_to_local_homeomorph f f' hf').symm
def
has_strict_fderiv_at.implicit_function
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
Implicit function `g` defined by `f (g z y) = z`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph_fst (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (x : E) : (hf.implicit_to_local_homeomorph f f' hf' x).fst = f x
rfl
lemma
has_strict_fderiv_at.implicit_to_local_homeomorph_fst
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph_apply_ker (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) (y : ker f') : hf.implicit_to_local_homeomorph f f' hf' (y + a) = (f (y + a), y)
by apply implicit_to_local_homeomorph_of_complemented_apply_ker
lemma
has_strict_fderiv_at.implicit_to_local_homeomorph_apply_ker
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
implicit_to_local_homeomorph_self (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) : hf.implicit_to_local_homeomorph f f' hf' a = (f a, 0)
by apply implicit_to_local_homeomorph_of_complemented_self
lemma
has_strict_fderiv_at.implicit_to_local_homeomorph_self
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_implicit_to_local_homeomorph_source (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) : a ∈ (hf.implicit_to_local_homeomorph f f' hf').source
mem_to_local_homeomorph_source _
lemma
has_strict_fderiv_at.mem_implicit_to_local_homeomorph_source
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_implicit_to_local_homeomorph_target (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) : (f a, (0 : ker f')) ∈ (hf.implicit_to_local_homeomorph f f' hf').target
by apply mem_implicit_to_local_homeomorph_of_complemented_target
lemma
has_strict_fderiv_at.mem_implicit_to_local_homeomorph_target
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_implicit_function (hf : has_strict_fderiv_at f f' a) (hf' : range f' = ⊤) {α : Type*} {l : filter α} {g₁ : α → F} {g₂ : α → ker f'} (h₁ : tendsto g₁ l (𝓝 $ f a)) (h₂ : tendsto g₂ l (𝓝 0)) : tendsto (λ t, hf.implicit_function f f' hf' (g₁ t) (g₂ t)) l (𝓝 a)
begin refine ((hf.implicit_to_local_homeomorph f f' hf').tendsto_symm (hf.mem_implicit_to_local_homeomorph_source hf')).comp _, rw [implicit_to_local_homeomorph_self], exact h₁.prod_mk_nhds h₂ end
lemma
has_strict_fderiv_at.tendsto_implicit_function
analysis.calculus
src/analysis/calculus/implicit.lean
[ "analysis.calculus.inverse", "analysis.normed_space.complemented" ]
[ "filter", "has_strict_fderiv_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83