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circle_integral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable {c : ℂ} {r R : ℝ} (h0 : 0 < r) (hle : r ≤ R) {f : ℂ → E} {s : set ℂ} (hs : s.countable) (hc : continuous_on f (closed_ball c R \ ball c r)) (hd : ∀ z ∈ ball c R \ closed_ball c r \ s, differentiable_at ℂ f z) : ∮ z in C(c, R), (z ...
begin /- We apply the previous lemma to `λ z, f (c + exp z)` on the rectangle `[log r, log R] × [0, 2 * π]`. -/ set A := closed_ball c R \ ball c r, obtain ⟨a, rfl⟩ : ∃ a, real.exp a = r, from ⟨real.log r, real.exp_log h0⟩, obtain ⟨b, rfl⟩ : ∃ b, real.exp b = R, from ⟨real.log R, real.exp_log (h0.trans_le hle...
lemma
complex.circle_integral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "circle_integral", "circle_map", "circle_map_ne_center", "circle_map_sub_center", "continuous_on", "countable", "deriv_circle_map", "differentiable", "differentiable_at", "div_eq_mul_inv", "exp", "exp_add", "mul_div_cancel_left", "real.exp", "real.exp_le_exp", "real.exp_log", "real.e...
If `f : ℂ → E` is continuous the closed annulus `r ≤ ‖z - c‖ ≤ R`, `0 < r ≤ R`, and is complex differentiable at all but countably many points of its interior, then the integrals of `f z / (z - c)` (formally, `(z - c)⁻¹ • f z`) over the circles `‖z - c‖ = r` and `‖z - c‖ = R` are equal to each other.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle_integral_eq_of_differentiable_on_annulus_off_countable {c : ℂ} {r R : ℝ} (h0 : 0 < r) (hle : r ≤ R) {f : ℂ → E} {s : set ℂ} (hs : s.countable) (hc : continuous_on f (closed_ball c R \ ball c r)) (hd : ∀ z ∈ ball c R \ closed_ball c r \ s, differentiable_at ℂ f z) : ∮ z in C(c, R), f z = ∮ z in C(c, r), f...
calc ∮ z in C(c, R), f z = ∮ z in C(c, R), (z - c)⁻¹ • (z - c) • f z : (circle_integral.integral_sub_inv_smul_sub_smul _ _ _ _).symm ... = ∮ z in C(c, r), (z - c)⁻¹ • (z - c) • f z : circle_integral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable h0 hle hs ((continuous_on_id.sub continuous_on_...
lemma
complex.circle_integral_eq_of_differentiable_on_annulus_off_countable
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "circle_integral.integral_sub_inv_smul_sub_smul", "continuous_on", "continuous_on_const", "differentiable_at" ]
**Cauchy-Goursat theorem** for an annulus. If `f : ℂ → E` is continuous on the closed annulus `r ≤ ‖z - c‖ ≤ R`, `0 < r ≤ R`, and is complex differentiable at all but countably many points of its interior, then the integrals of `f` over the circles `‖z - c‖ = r` and `‖z - c‖ = R` are equal to each other.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle_integral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto {c : ℂ} {R : ℝ} (h0 : 0 < R) {f : ℂ → E} {y : E} {s : set ℂ} (hs : s.countable) (hc : continuous_on f (closed_ball c R \ {c})) (hd : ∀ z ∈ ball c R \ {c} \ s, differentiable_at ℂ f z) (hy : tendsto f (𝓝[{c}ᶜ] c) (𝓝 y)) : ∮ z in ...
begin rw [← sub_eq_zero, ← norm_le_zero_iff], refine le_of_forall_le_of_dense (λ ε ε0, _), obtain ⟨δ, δ0, hδ⟩ : ∃ δ > (0 : ℝ), ∀ z ∈ closed_ball c δ \ {c}, dist (f z) y < ε / (2 * π), from ((nhds_within_has_basis nhds_basis_closed_ball _).tendsto_iff nhds_basis_ball).1 hy _ (div_pos ε0 real.two_pi_p...
lemma
complex.circle_integral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "circle_integrable", "circle_integral.integral_sub", "circle_integral.norm_integral_le_of_norm_le_const", "continuous_on", "continuous_on_const", "differentiable_at", "dist_self", "div_pos", "le_of_forall_le_of_dense", "mul_le_mul_of_nonneg_left", "ne_of_mem_of_not_mem", "nhds_within_has_basis...
**Cauchy integral formula** for the value at the center of a disc. If `f` is continuous on a punctured closed disc of radius `R`, is differentiable at all but countably many points of the interior of this disc, and has a limit `y` at the center of the disc, then the integral $\oint_{‖z-c‖=R} \frac{f(z)}{z-c}\,dz$ is eq...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle_integral_sub_center_inv_smul_of_differentiable_on_off_countable {R : ℝ} (h0 : 0 < R) {f : ℂ → E} {c : ℂ} {s : set ℂ} (hs : s.countable) (hc : continuous_on f (closed_ball c R)) (hd : ∀ z ∈ ball c R \ s, differentiable_at ℂ f z) : ∮ z in C(c, R), (z - c)⁻¹ • f z = (2 * π * I : ℂ) • f c
circle_integral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto h0 hs (hc.mono $ diff_subset _ _) (λ z hz, hd z ⟨hz.1.1, hz.2⟩) (hc.continuous_at $ closed_ball_mem_nhds _ h0).continuous_within_at
lemma
complex.circle_integral_sub_center_inv_smul_of_differentiable_on_off_countable
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "continuous_on", "continuous_within_at", "differentiable_at" ]
**Cauchy integral formula** for the value at the center of a disc. If `f : ℂ → E` is continuous on a closed disc of radius `R` and is complex differentiable at all but countably many points of its interior, then the integral $\oint_{|z-c|=R} \frac{f(z)}{z-c}\,dz$ is equal to $2πiy`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle_integral_eq_zero_of_differentiable_on_off_countable {R : ℝ} (h0 : 0 ≤ R) {f : ℂ → E} {c : ℂ} {s : set ℂ} (hs : s.countable) (hc : continuous_on f (closed_ball c R)) (hd : ∀ z ∈ ball c R \ s, differentiable_at ℂ f z) : ∮ z in C(c, R), f z = 0
begin rcases h0.eq_or_lt with rfl|h0, { apply circle_integral.integral_radius_zero }, calc ∮ z in C(c, R), f z = ∮ z in C(c, R), (z - c)⁻¹ • (z - c) • f z : (circle_integral.integral_sub_inv_smul_sub_smul _ _ _ _).symm ... = (2 * ↑π * I : ℂ) • (c - c) • f c : circle_integral_sub_center_inv_smul_of_differe...
lemma
complex.circle_integral_eq_zero_of_differentiable_on_off_countable
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "circle_integral.integral_radius_zero", "circle_integral.integral_sub_inv_smul_sub_smul", "continuous_on", "continuous_on_const", "differentiable_at", "smul_zero", "zero_smul" ]
**Cauchy-Goursat theorem** for a disk: if `f : ℂ → E` is continuous on a closed disk `{z | ‖z - c‖ ≤ R}` and is complex differentiable at all but countably many points of its interior, then the integral $\oint_{|z-c|=R}f(z)\,dz$ equals zero.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle_integral_sub_inv_smul_of_differentiable_on_off_countable_aux {R : ℝ} {c w : ℂ} {f : ℂ → E} {s : set ℂ} (hs : s.countable) (hw : w ∈ ball c R \ s) (hc : continuous_on f (closed_ball c R)) (hd : ∀ x ∈ ball c R \ s, differentiable_at ℂ f x) : ∮ z in C(c, R), (z - w)⁻¹ • f z = (2 * π * I : ℂ) • f w
begin have hR : 0 < R := dist_nonneg.trans_lt hw.1, set F : ℂ → E := dslope f w, have hws : (insert w s).countable := hs.insert w, have hnhds : closed_ball c R ∈ 𝓝 w, from closed_ball_mem_nhds_of_mem hw.1, have hcF : continuous_on F (closed_ball c R), from (continuous_on_dslope $ closed_ball_mem_nhds_of_...
lemma
complex.circle_integral_sub_inv_smul_of_differentiable_on_off_countable_aux
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "circle_integrable", "circle_integral.integral_congr", "circle_integral.integral_smul_const", "circle_integral.integral_sub", "circle_integral.integral_sub_inv_of_mem_ball", "continuous_on", "continuous_on_const", "continuous_on_dslope", "countable", "differentiable_at", "differentiable_at_dslop...
An auxiliary lemma for `complex.circle_integral_sub_inv_smul_of_differentiable_on_off_countable`. This lemma assumes `w ∉ s` while the main lemma drops this assumption.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
two_pi_I_inv_smul_circle_integral_sub_inv_smul_of_differentiable_on_off_countable {R : ℝ} {c w : ℂ} {f : ℂ → E} {s : set ℂ} (hs : s.countable) (hw : w ∈ ball c R) (hc : continuous_on f (closed_ball c R)) (hd : ∀ x ∈ ball c R \ s, differentiable_at ℂ f x) : (2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - w)⁻¹ • f z = f w
begin have hR : 0 < R := dist_nonneg.trans_lt hw, suffices : w ∈ closure (ball c R \ s), { lift R to ℝ≥0 using hR.le, have A : continuous_at (λ w, (2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - w)⁻¹ • f z) w, { have := has_fpower_series_on_cauchy_integral ((hc.mono sphere_subset_closed_ball).circle_integr...
lemma
complex.two_pi_I_inv_smul_circle_integral_sub_inv_smul_of_differentiable_on_off_countable
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "cardinal.aleph_0_lt_continuum", "cardinal.le_aleph_0_iff_set_countable", "cardinal.mk_Ioo_real", "circle_integrable", "closure", "continuous_at", "continuous_on", "countable", "differentiable_at", "has_fpower_series_on_cauchy_integral", "inv_smul_smul₀", "lift", "metric.emetric_ball_nnreal"...
**Cauchy integral formula**: if `f : ℂ → E` is continuous on a closed disc of radius `R` and is complex differentiable at all but countably many points of its interior, then for any `w` in this interior we have $\frac{1}{2πi}\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=f(w)$.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle_integral_sub_inv_smul_of_differentiable_on_off_countable {R : ℝ} {c w : ℂ} {f : ℂ → E} {s : set ℂ} (hs : s.countable) (hw : w ∈ ball c R) (hc : continuous_on f (closed_ball c R)) (hd : ∀ x ∈ ball c R \ s, differentiable_at ℂ f x) : ∮ z in C(c, R), (z - w)⁻¹ • f z = (2 * π * I : ℂ) • f w
by { rw [← two_pi_I_inv_smul_circle_integral_sub_inv_smul_of_differentiable_on_off_countable hs hw hc hd, smul_inv_smul₀], simp [real.pi_ne_zero, I_ne_zero] }
lemma
complex.circle_integral_sub_inv_smul_of_differentiable_on_off_countable
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "continuous_on", "differentiable_at", "real.pi_ne_zero", "smul_inv_smul₀" ]
**Cauchy integral formula**: if `f : ℂ → E` is continuous on a closed disc of radius `R` and is complex differentiable at all but countably many points of its interior, then for any `w` in this interior we have $\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=2πif(w)$.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.diff_cont_on_cl.circle_integral_sub_inv_smul {R : ℝ} {c w : ℂ} {f : ℂ → E} (h : diff_cont_on_cl ℂ f (ball c R)) (hw : w ∈ ball c R) : ∮ z in C(c, R), (z - w)⁻¹ • f z = (2 * π * I : ℂ) • f w
circle_integral_sub_inv_smul_of_differentiable_on_off_countable countable_empty hw h.continuous_on_ball $ λ x hx, h.differentiable_at is_open_ball hx.1
lemma
diff_cont_on_cl.circle_integral_sub_inv_smul
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "diff_cont_on_cl" ]
**Cauchy integral formula**: if `f : ℂ → E` is complex differentiable on an open disc and is continuous on its closure, then for any `w` in this open ball we have $\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=2πif(w)$.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.diff_cont_on_cl.two_pi_I_inv_smul_circle_integral_sub_inv_smul {R : ℝ} {c w : ℂ} {f : ℂ → E} (hf : diff_cont_on_cl ℂ f (ball c R)) (hw : w ∈ ball c R) : (2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - w)⁻¹ • f z = f w
begin have hR : 0 < R := not_le.mp (ball_eq_empty.not.mp (nonempty_of_mem hw).ne_empty), refine two_pi_I_inv_smul_circle_integral_sub_inv_smul_of_differentiable_on_off_countable countable_empty hw _ _, { simpa only [closure_ball c hR.ne.symm] using hf.continuous_on }, { simpa only [diff_empty] using λ z hz,...
lemma
diff_cont_on_cl.two_pi_I_inv_smul_circle_integral_sub_inv_smul
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "closure_ball", "diff_cont_on_cl" ]
**Cauchy integral formula**: if `f : ℂ → E` is complex differentiable on an open disc and is continuous on its closure, then for any `w` in this open ball we have $\frac{1}{2πi}\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=f(w)$.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.differentiable_on.circle_integral_sub_inv_smul {R : ℝ} {c w : ℂ} {f : ℂ → E} (hd : differentiable_on ℂ f (closed_ball c R)) (hw : w ∈ ball c R) : ∮ z in C(c, R), (z - w)⁻¹ • f z = (2 * π * I : ℂ) • f w
(hd.mono closure_ball_subset_closed_ball).diff_cont_on_cl.circle_integral_sub_inv_smul hw
lemma
differentiable_on.circle_integral_sub_inv_smul
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "diff_cont_on_cl.circle_integral_sub_inv_smul", "differentiable_on" ]
**Cauchy integral formula**: if `f : ℂ → E` is complex differentiable on a closed disc of radius `R`, then for any `w` in its interior we have $\oint_{|z-c|=R}(z-w)^{-1}f(z)\,dz=2πif(w)$.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle_integral_div_sub_of_differentiable_on_off_countable {R : ℝ} {c w : ℂ} {s : set ℂ} (hs : s.countable) (hw : w ∈ ball c R) {f : ℂ → ℂ} (hc : continuous_on f (closed_ball c R)) (hd : ∀ z ∈ ball c R \ s, differentiable_at ℂ f z) : ∮ z in C(c, R), f z / (z - w) = 2 * π * I * f w
by simpa only [smul_eq_mul, div_eq_inv_mul] using circle_integral_sub_inv_smul_of_differentiable_on_off_countable hs hw hc hd
lemma
complex.circle_integral_div_sub_of_differentiable_on_off_countable
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "continuous_on", "differentiable_at", "div_eq_inv_mul", "smul_eq_mul" ]
**Cauchy integral formula**: if `f : ℂ → ℂ` is continuous on a closed disc of radius `R` and is complex differentiable at all but countably many points of its interior, then for any `w` in this interior we have $\oint_{|z-c|=R}\frac{f(z)}{z-w}dz=2\pi i\,f(w)$.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_fpower_series_on_ball_of_differentiable_off_countable {R : ℝ≥0} {c : ℂ} {f : ℂ → E} {s : set ℂ} (hs : s.countable) (hc : continuous_on f (closed_ball c R)) (hd : ∀ z ∈ ball c R \ s, differentiable_at ℂ f z) (hR : 0 < R) : has_fpower_series_on_ball f (cauchy_power_series f c R) c R
{ r_le := le_radius_cauchy_power_series _ _ _, r_pos := ennreal.coe_pos.2 hR, has_sum := λ w hw, begin have hw' : c + w ∈ ball c R, by simpa only [add_mem_ball_iff_norm, ← coe_nnnorm, mem_emetric_ball_zero_iff, nnreal.coe_lt_coe, ennreal.coe_lt_coe] using hw, rw ← two_pi_I_inv_smul...
lemma
complex.has_fpower_series_on_ball_of_differentiable_off_countable
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "cauchy_power_series", "circle_integrable", "continuous_on", "differentiable_at", "ennreal.coe_lt_coe", "has_fpower_series_on_ball", "has_fpower_series_on_cauchy_integral", "has_sum", "le_radius_cauchy_power_series", "nnreal.coe_lt_coe" ]
If `f : ℂ → E` is continuous on a closed ball of positive radius and is differentiable at all but countably many points of the corresponding open ball, then it is analytic on the open ball with coefficients of the power series given by Cauchy integral formulas.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.diff_cont_on_cl.has_fpower_series_on_ball {R : ℝ≥0} {c : ℂ} {f : ℂ → E} (hf : diff_cont_on_cl ℂ f (ball c R)) (hR : 0 < R) : has_fpower_series_on_ball f (cauchy_power_series f c R) c R
has_fpower_series_on_ball_of_differentiable_off_countable countable_empty hf.continuous_on_ball (λ z hz, hf.differentiable_at is_open_ball hz.1) hR
lemma
diff_cont_on_cl.has_fpower_series_on_ball
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "cauchy_power_series", "diff_cont_on_cl", "has_fpower_series_on_ball" ]
If `f : ℂ → E` is complex differentiable on an open disc of positive radius and is continuous on its closure, then it is analytic on the open disc with coefficients of the power series given by Cauchy integral formulas.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.differentiable_on.has_fpower_series_on_ball {R : ℝ≥0} {c : ℂ} {f : ℂ → E} (hd : differentiable_on ℂ f (closed_ball c R)) (hR : 0 < R) : has_fpower_series_on_ball f (cauchy_power_series f c R) c R
(hd.mono closure_ball_subset_closed_ball).diff_cont_on_cl.has_fpower_series_on_ball hR
lemma
differentiable_on.has_fpower_series_on_ball
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "cauchy_power_series", "diff_cont_on_cl.has_fpower_series_on_ball", "differentiable_on", "has_fpower_series_on_ball" ]
If `f : ℂ → E` is complex differentiable on a closed disc of positive radius, then it is analytic on the corresponding open disc, and the coefficients of the power series are given by Cauchy integral formulas. See also `complex.has_fpower_series_on_ball_of_differentiable_off_countable` for a version of this lemma with ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.differentiable_on.analytic_at {s : set ℂ} {f : ℂ → E} {z : ℂ} (hd : differentiable_on ℂ f s) (hz : s ∈ 𝓝 z) : analytic_at ℂ f z
begin rcases nhds_basis_closed_ball.mem_iff.1 hz with ⟨R, hR0, hRs⟩, lift R to ℝ≥0 using hR0.le, exact ((hd.mono hRs).has_fpower_series_on_ball hR0).analytic_at end
lemma
differentiable_on.analytic_at
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "analytic_at", "differentiable_on", "has_fpower_series_on_ball", "lift" ]
If `f : ℂ → E` is complex differentiable on some set `s`, then it is analytic at any point `z` such that `s ∈ 𝓝 z` (equivalently, `z ∈ interior s`).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.differentiable_on.analytic_on {s : set ℂ} {f : ℂ → E} (hd : differentiable_on ℂ f s) (hs : is_open s) : analytic_on ℂ f s
λ z hz, hd.analytic_at (hs.mem_nhds hz)
lemma
differentiable_on.analytic_on
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "analytic_on", "differentiable_on", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.differentiable.analytic_at {f : ℂ → E} (hf : differentiable ℂ f) (z : ℂ) : analytic_at ℂ f z
hf.differentiable_on.analytic_at univ_mem
lemma
differentiable.analytic_at
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "analytic_at", "differentiable" ]
A complex differentiable function `f : ℂ → E` is analytic at every point.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.differentiable.has_fpower_series_on_ball {f : ℂ → E} (h : differentiable ℂ f) (z : ℂ) {R : ℝ≥0} (hR : 0 < R) : has_fpower_series_on_ball f (cauchy_power_series f z R) z ∞
(h.differentiable_on.has_fpower_series_on_ball hR).r_eq_top_of_exists $ λ r hr, ⟨_, h.differentiable_on.has_fpower_series_on_ball hr⟩
lemma
differentiable.has_fpower_series_on_ball
analysis.complex
src/analysis/complex/cauchy_integral.lean
[ "measure_theory.measure.lebesgue.complex", "measure_theory.integral.divergence_theorem", "measure_theory.integral.circle_integral", "analysis.calculus.dslope", "analysis.analytic.basic", "analysis.complex.re_im_topology", "analysis.calculus.diff_cont_on_cl", "data.real.cardinality" ]
[ "cauchy_power_series", "differentiable", "has_fpower_series_on_ball" ]
When `f : ℂ → E` is differentiable, the `cauchy_power_series f z R` represents `f` as a power series centered at `z` in the entirety of `ℂ`, regardless of `R : ℝ≥0`, with `0 < R`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle : submonoid ℂ
submonoid.unit_sphere ℂ
def
circle
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "submonoid", "submonoid.unit_sphere" ]
The unit circle in `ℂ`, here given the structure of a submonoid of `ℂ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_circle_iff_abs {z : ℂ} : z ∈ circle ↔ abs z = 1
mem_sphere_zero_iff_norm
lemma
mem_circle_iff_abs
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle_def : ↑circle = {z : ℂ | abs z = 1}
set.ext $ λ z, mem_circle_iff_abs
lemma
circle_def
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "mem_circle_iff_abs", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
abs_coe_circle (z : circle) : abs z = 1
mem_circle_iff_abs.mp z.2
lemma
abs_coe_circle
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_circle_iff_norm_sq {z : ℂ} : z ∈ circle ↔ norm_sq z = 1
by simp [complex.abs]
lemma
mem_circle_iff_norm_sq
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle", "complex.abs" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_sq_eq_of_mem_circle (z : circle) : norm_sq z = 1
by simp [norm_sq_eq_abs]
lemma
norm_sq_eq_of_mem_circle
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ne_zero_of_mem_circle (z : circle) : (z:ℂ) ≠ 0
ne_zero_of_mem_unit_sphere z
lemma
ne_zero_of_mem_circle
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_inv_circle (z : circle) : ↑(z⁻¹) = (z : ℂ)⁻¹
rfl
lemma
coe_inv_circle
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_inv_circle_eq_conj (z : circle) : ↑(z⁻¹) = conj (z : ℂ)
by rw [coe_inv_circle, inv_def, norm_sq_eq_of_mem_circle, inv_one, of_real_one, mul_one]
lemma
coe_inv_circle_eq_conj
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle", "coe_inv_circle", "inv_one", "mul_one", "norm_sq_eq_of_mem_circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_div_circle (z w : circle) : ↑(z / w) = (z:ℂ) / w
circle.subtype.map_div z w
lemma
coe_div_circle
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle.to_units : circle →* units ℂ
unit_sphere_to_units ℂ
def
circle.to_units
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle", "unit_sphere_to_units", "units" ]
The elements of the circle embed into the units.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle.to_units_apply (z : circle) : circle.to_units z = units.mk0 z (ne_zero_of_mem_circle z)
rfl
lemma
circle.to_units_apply
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle", "circle.to_units", "ne_zero_of_mem_circle", "units.mk0" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
circle.of_conj_div_self (z : ℂ) (hz : z ≠ 0) : circle
⟨conj z / z, mem_circle_iff_abs.2 $ by rw [map_div₀, abs_conj, div_self (complex.abs.ne_zero hz)]⟩
def
circle.of_conj_div_self
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle", "div_self", "map_div₀" ]
If `z` is a nonzero complex number, then `conj z / z` belongs to the unit circle.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exp_map_circle : C(ℝ, circle)
{ to_fun := λ t, ⟨exp (t * I), by simp [exp_mul_I, abs_cos_add_sin_mul_I]⟩ }
def
exp_map_circle
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "circle" ]
The map `λ t, exp (t * I)` from `ℝ` to the unit circle in `ℂ`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exp_map_circle_apply (t : ℝ) : ↑(exp_map_circle t) = complex.exp (t * complex.I)
rfl
lemma
exp_map_circle_apply
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "complex.I", "complex.exp", "exp_map_circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exp_map_circle_zero : exp_map_circle 0 = 1
subtype.ext $ by rw [exp_map_circle_apply, of_real_zero, zero_mul, exp_zero, submonoid.coe_one]
lemma
exp_map_circle_zero
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "exp_map_circle", "exp_map_circle_apply", "exp_zero", "submonoid.coe_one", "subtype.ext", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exp_map_circle_add (x y : ℝ) : exp_map_circle (x + y) = exp_map_circle x * exp_map_circle y
subtype.ext $ by simp only [exp_map_circle_apply, submonoid.coe_mul, of_real_add, add_mul, complex.exp_add]
lemma
exp_map_circle_add
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "complex.exp_add", "exp_map_circle", "exp_map_circle_apply", "submonoid.coe_mul", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exp_map_circle_hom : ℝ →+ (additive circle)
{ to_fun := additive.of_mul ∘ exp_map_circle, map_zero' := exp_map_circle_zero, map_add' := exp_map_circle_add }
def
exp_map_circle_hom
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "additive", "additive.of_mul", "circle", "exp_map_circle", "exp_map_circle_add", "exp_map_circle_zero" ]
The map `λ t, exp (t * I)` from `ℝ` to the unit circle in `ℂ`, considered as a homomorphism of groups.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exp_map_circle_sub (x y : ℝ) : exp_map_circle (x - y) = exp_map_circle x / exp_map_circle y
exp_map_circle_hom.map_sub x y
lemma
exp_map_circle_sub
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "exp_map_circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exp_map_circle_neg (x : ℝ) : exp_map_circle (-x) = (exp_map_circle x)⁻¹
exp_map_circle_hom.map_neg x
lemma
exp_map_circle_neg
analysis.complex
src/analysis/complex/circle.lean
[ "analysis.special_functions.exp", "topology.continuous_function.basic", "analysis.normed.field.unit_ball" ]
[ "exp_map_circle" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_conformal_map_conj : is_conformal_map (conj_lie : ℂ →L[ℝ] ℂ)
conj_lie.to_linear_isometry.is_conformal_map
lemma
is_conformal_map_conj
analysis.complex
src/analysis/complex/conformal.lean
[ "analysis.complex.isometry", "analysis.normed_space.conformal_linear_map", "analysis.normed_space.finite_dimension" ]
[ "is_conformal_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_conformal_map_complex_linear {map : ℂ →L[ℂ] E} (nonzero : map ≠ 0) : is_conformal_map (map.restrict_scalars ℝ)
begin have minor₁ : ‖map 1‖ ≠ 0, { simpa only [ext_ring_iff, ne.def, norm_eq_zero] using nonzero}, refine ⟨‖map 1‖, minor₁, ⟨‖map 1‖⁻¹ • map, _⟩, _⟩, { intros x, simp only [linear_map.smul_apply], have : x = x • 1 := by rw [smul_eq_mul, mul_one], nth_rewrite 0 [this], rw [_root_.coe_coe map, lin...
lemma
is_conformal_map_complex_linear
analysis.complex
src/analysis/complex/conformal.lean
[ "analysis.complex.isometry", "analysis.normed_space.conformal_linear_map", "analysis.normed_space.finite_dimension" ]
[ "continuous_linear_map.coe_coe", "is_conformal_map", "linear_isometry.coe_mk", "linear_isometry.coe_to_continuous_linear_map", "linear_map.coe_coe_is_scalar_tower", "linear_map.smul_apply", "mul_one", "norm_eq_zero", "norm_inv", "norm_norm", "norm_smul", "one_mul", "pi.smul_apply", "smul_e...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_conformal_map_complex_linear_conj {map : ℂ →L[ℂ] E} (nonzero : map ≠ 0) : is_conformal_map ((map.restrict_scalars ℝ).comp (conj_cle : ℂ →L[ℝ] ℂ))
(is_conformal_map_complex_linear nonzero).comp is_conformal_map_conj
lemma
is_conformal_map_complex_linear_conj
analysis.complex
src/analysis/complex/conformal.lean
[ "analysis.complex.isometry", "analysis.normed_space.conformal_linear_map", "analysis.normed_space.finite_dimension" ]
[ "is_conformal_map", "is_conformal_map_complex_linear", "is_conformal_map_conj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_conformal_map.is_complex_or_conj_linear (h : is_conformal_map g) : (∃ (map : ℂ →L[ℂ] ℂ), map.restrict_scalars ℝ = g) ∨ (∃ (map : ℂ →L[ℂ] ℂ), map.restrict_scalars ℝ = g ∘L ↑conj_cle)
begin rcases h with ⟨c, hc, li, rfl⟩, obtain ⟨li, rfl⟩ : ∃ li' : ℂ ≃ₗᵢ[ℝ] ℂ, li'.to_linear_isometry = li, from ⟨li.to_linear_isometry_equiv rfl, by { ext1, refl }⟩, rcases linear_isometry_complex li with ⟨a, rfl|rfl⟩, -- let rot := c • (a : ℂ) • continuous_linear_map.id ℂ ℂ, { refine or.inl ⟨c • (a : ℂ) •...
lemma
is_conformal_map.is_complex_or_conj_linear
analysis.complex
src/analysis/complex/conformal.lean
[ "analysis.complex.isometry", "analysis.normed_space.conformal_linear_map", "analysis.normed_space.finite_dimension" ]
[ "continuous_linear_equiv.coe_coe", "continuous_linear_map.id", "is_conformal_map", "linear_isometry.coe_to_continuous_linear_map", "linear_isometry_complex", "linear_isometry_equiv.coe_to_linear_isometry", "linear_isometry_equiv.trans_apply", "rotation_apply", "smul_eq_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_conformal_map_iff_is_complex_or_conj_linear: is_conformal_map g ↔ ((∃ (map : ℂ →L[ℂ] ℂ), map.restrict_scalars ℝ = g) ∨ (∃ (map : ℂ →L[ℂ] ℂ), map.restrict_scalars ℝ = g ∘L ↑conj_cle)) ∧ g ≠ 0
begin split, { exact λ h, ⟨h.is_complex_or_conj_linear, h.ne_zero⟩, }, { rintros ⟨⟨map, rfl⟩ | ⟨map, hmap⟩, h₂⟩, { refine is_conformal_map_complex_linear _, contrapose! h₂ with w, simp only [w, restrict_scalars_zero]}, { have minor₁ : g = (map.restrict_scalars ℝ) ∘L ↑conj_cle, { ext1, ...
lemma
is_conformal_map_iff_is_complex_or_conj_linear
analysis.complex
src/analysis/complex/conformal.lean
[ "analysis.complex.isometry", "analysis.normed_space.conformal_linear_map", "analysis.normed_space.finite_dimension" ]
[ "continuous_linear_equiv.coe_coe", "is_conformal_map", "is_conformal_map_complex_linear", "is_conformal_map_complex_linear_conj", "star_ring_end_self_apply" ]
A real continuous linear map on the complex plane is conformal if and only if the map or its conjugate is complex linear, and the map is nonvanishing.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rotation : circle →* (ℂ ≃ₗᵢ[ℝ] ℂ)
{ to_fun := λ a, { norm_map' := λ x, show |a * x| = |x|, by rw [map_mul, abs_coe_circle, one_mul], ..distrib_mul_action.to_linear_equiv ℝ ℂ a }, map_one' := linear_isometry_equiv.ext $ one_smul _, map_mul' := λ _ _, linear_isometry_equiv.ext $ mul_smul _ _ }
def
rotation
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "abs_coe_circle", "circle", "distrib_mul_action.to_linear_equiv", "linear_isometry_equiv.ext", "map_mul", "one_mul", "one_smul" ]
An element of the unit circle defines a `linear_isometry_equiv` from `ℂ` to itself, by rotation.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rotation_apply (a : circle) (z : ℂ) : rotation a z = a * z
rfl
lemma
rotation_apply
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "rotation" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rotation_symm (a : circle) : (rotation a).symm = rotation a⁻¹
linear_isometry_equiv.ext $ λ x, rfl
lemma
rotation_symm
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "linear_isometry_equiv.ext", "rotation" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rotation_trans (a b : circle) : (rotation a).trans (rotation b) = rotation (b * a)
by { ext1, simp }
lemma
rotation_trans
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "rotation" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rotation_ne_conj_lie (a : circle) : rotation a ≠ conj_lie
begin intro h, have h1 : rotation a 1 = conj 1 := linear_isometry_equiv.congr_fun h 1, have hI : rotation a I = conj I := linear_isometry_equiv.congr_fun h I, rw [rotation_apply, ring_hom.map_one, mul_one] at h1, rw [rotation_apply, conj_I, ← neg_one_mul, mul_left_inj' I_ne_zero, h1, eq_neg_self_iff] at hI, ...
lemma
rotation_ne_conj_lie
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "eq_neg_self_iff", "linear_isometry_equiv.congr_fun", "mul_left_inj'", "mul_one", "neg_one_mul", "one_ne_zero", "ring_hom.map_one", "rotation", "rotation_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rotation_of (e : ℂ ≃ₗᵢ[ℝ] ℂ) : circle
⟨(e 1) / complex.abs (e 1), by simp⟩
def
rotation_of
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "complex.abs" ]
Takes an element of `ℂ ≃ₗᵢ[ℝ] ℂ` and checks if it is a rotation, returns an element of the unit circle.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rotation_of_rotation (a : circle) : rotation_of (rotation a) = a
subtype.ext $ by simp
lemma
rotation_of_rotation
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "rotation", "rotation_of", "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rotation_injective : function.injective rotation
function.left_inverse.injective rotation_of_rotation
lemma
rotation_injective
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "rotation", "rotation_of_rotation" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry.re_apply_eq_re_of_add_conj_eq (f : ℂ →ₗᵢ[ℝ] ℂ) (h₃ : ∀ z, z + conj z = f z + conj (f z)) (z : ℂ) : (f z).re = z.re
by simpa [ext_iff, add_re, add_im, conj_re, conj_im, ←two_mul, (show (2 : ℝ) ≠ 0, by simp [two_ne_zero])] using (h₃ z).symm
lemma
linear_isometry.re_apply_eq_re_of_add_conj_eq
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "two_ne_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry.im_apply_eq_im_or_neg_of_re_apply_eq_re {f : ℂ →ₗᵢ[ℝ] ℂ} (h₂ : ∀ z, (f z).re = z.re) (z : ℂ) : (f z).im = z.im ∨ (f z).im = -z.im
begin have h₁ := f.norm_map z, simp only [complex.abs_def, norm_eq_abs] at h₁, rwa [real.sqrt_inj (norm_sq_nonneg _) (norm_sq_nonneg _), norm_sq_apply (f z), norm_sq_apply z, h₂, add_left_cancel_iff, mul_self_eq_mul_self_iff] at h₁, end
lemma
linear_isometry.im_apply_eq_im_or_neg_of_re_apply_eq_re
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "complex.abs_def", "mul_self_eq_mul_self_iff", "real.sqrt_inj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry.im_apply_eq_im {f : ℂ →ₗᵢ[ℝ] ℂ} (h : f 1 = 1) (z : ℂ) : z + conj z = f z + conj (f z)
begin have : ‖f z - 1‖ = ‖z - 1‖ := by rw [← f.norm_map (z - 1), f.map_sub, h], apply_fun λ x, x ^ 2 at this, simp only [norm_eq_abs, ←norm_sq_eq_abs] at this, rw [←of_real_inj, ←mul_conj, ←mul_conj] at this, rw [ring_hom.map_sub, ring_hom.map_sub] at this, simp only [sub_mul, mul_sub, one_mul, mul_one] at ...
lemma
linear_isometry.im_apply_eq_im
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "linear_isometry.norm_map", "mul_one", "one_mul", "ring_hom.map_one", "ring_hom.map_sub" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry.re_apply_eq_re {f : ℂ →ₗᵢ[ℝ] ℂ} (h : f 1 = 1) (z : ℂ) : (f z).re = z.re
begin apply linear_isometry.re_apply_eq_re_of_add_conj_eq, intro z, apply linear_isometry.im_apply_eq_im h, end
lemma
linear_isometry.re_apply_eq_re
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "linear_isometry.im_apply_eq_im", "linear_isometry.re_apply_eq_re_of_add_conj_eq" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry_complex_aux {f : ℂ ≃ₗᵢ[ℝ] ℂ} (h : f 1 = 1) : f = linear_isometry_equiv.refl ℝ ℂ ∨ f = conj_lie
begin have h0 : f I = I ∨ f I = -I, { have : |f I| = 1 := by simpa using f.norm_map complex.I, simp only [ext_iff, ←and_or_distrib_left, neg_re, I_re, neg_im, neg_zero], split, { rw ←I_re, exact @linear_isometry.re_apply_eq_re f.to_linear_isometry h I, }, { apply @linear_isometry.im_apply_eq_i...
lemma
linear_isometry_complex_aux
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "complex.I", "linear_isometry.im_apply_eq_im_or_neg_of_re_apply_eq_re", "linear_isometry.re_apply_eq_re", "linear_isometry_equiv.refl", "linear_isometry_equiv.to_linear_equiv_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_isometry_complex (f : ℂ ≃ₗᵢ[ℝ] ℂ) : ∃ a : circle, f = rotation a ∨ f = conj_lie.trans (rotation a)
begin let a : circle := ⟨f 1, by simpa using f.norm_map 1⟩, use a, have : (f.trans (rotation a).symm) 1 = 1, { simpa using rotation_apply a⁻¹ (f 1) }, refine (linear_isometry_complex_aux this).imp (λ h₁, _) (λ h₂, _), { simpa using eq_mul_of_inv_mul_eq h₁ }, { exact eq_mul_of_inv_mul_eq h₂ } end
lemma
linear_isometry_complex
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "eq_mul_of_inv_mul_eq", "linear_isometry_complex_aux", "rotation", "rotation_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_matrix_rotation (a : circle) : linear_map.to_matrix basis_one_I basis_one_I (rotation a).to_linear_equiv = matrix.plane_conformal_matrix (re a) (im a) (by simp [pow_two, ←norm_sq_apply])
begin ext i j, simp [linear_map.to_matrix_apply], fin_cases i; fin_cases j; simp end
lemma
to_matrix_rotation
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "linear_map.to_matrix", "linear_map.to_matrix_apply", "matrix.plane_conformal_matrix", "pow_two", "rotation" ]
The matrix representation of `rotation a` is equal to the conformal matrix `!![re a, -im a; im a, re a]`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
det_rotation (a : circle) : ((rotation a).to_linear_equiv : ℂ →ₗ[ℝ] ℂ).det = 1
begin rw [←linear_map.det_to_matrix basis_one_I, to_matrix_rotation, matrix.det_fin_two], simp [←norm_sq_apply] end
lemma
det_rotation
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "matrix.det_fin_two", "rotation", "to_matrix_rotation" ]
The determinant of `rotation` (as a linear map) is equal to `1`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_equiv_det_rotation (a : circle) : (rotation a).to_linear_equiv.det = 1
by rw [←units.eq_iff, linear_equiv.coe_det, det_rotation, units.coe_one]
lemma
linear_equiv_det_rotation
analysis.complex
src/analysis/complex/isometry.lean
[ "analysis.complex.circle", "linear_algebra.determinant", "linear_algebra.matrix.general_linear_group" ]
[ "circle", "det_rotation", "linear_equiv.coe_det", "rotation", "units.coe_one" ]
The determinant of `rotation` (as a linear equiv) is equal to `1`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_eq_smul_circle_integral [complete_space F] {R : ℝ} {c : ℂ} {f : ℂ → F} (hR : 0 < R) (hf : diff_cont_on_cl ℂ f (ball c R)) : deriv f c = (2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - c) ^ (-2 : ℤ) • f z
begin lift R to ℝ≥0 using hR.le, refine (hf.has_fpower_series_on_ball hR).has_fpower_series_at.deriv.trans _, simp only [cauchy_power_series_apply, one_div, zpow_neg, pow_one, smul_smul, zpow_two, mul_inv] end
lemma
complex.deriv_eq_smul_circle_integral
analysis.complex
src/analysis/complex/liouville.lean
[ "analysis.complex.cauchy_integral", "analysis.calculus.fderiv_analytic", "analysis.normed_space.completion" ]
[ "cauchy_power_series_apply", "complete_space", "deriv", "diff_cont_on_cl", "lift", "mul_inv", "one_div", "pow_one", "smul_smul", "zpow_neg", "zpow_two" ]
If `f` is complex differentiable on an open disc with center `c` and radius `R > 0` and is continuous on its closure, then `f' c` can be represented as an integral over the corresponding circle. TODO: add a version for `w ∈ metric.ball c R`. TODO: add a version for higher derivatives.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_deriv_le_aux [complete_space F] {c : ℂ} {R C : ℝ} {f : ℂ → F} (hR : 0 < R) (hf : diff_cont_on_cl ℂ f (ball c R)) (hC : ∀ z ∈ sphere c R, ‖f z‖ ≤ C) : ‖deriv f c‖ ≤ C / R
begin have : ∀ z ∈ sphere c R, ‖(z - c) ^ (-2 : ℤ) • f z‖ ≤ C / (R * R), from λ z (hz : abs (z - c) = R), by simpa [-mul_inv_rev, norm_smul, hz, zpow_two, ←div_eq_inv_mul] using (div_le_div_right (mul_pos hR hR)).2 (hC z hz), calc ‖deriv f c‖ = ‖(2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - c) ^ (-2 : ℤ) • f z...
lemma
complex.norm_deriv_le_aux
analysis.complex
src/analysis/complex/liouville.lean
[ "analysis.complex.cauchy_integral", "analysis.calculus.fderiv_analytic", "analysis.normed_space.completion" ]
[ "circle_integral.norm_two_pi_I_inv_smul_integral_le_of_norm_le_const", "complete_space", "diff_cont_on_cl", "div_eq_mul_inv", "div_le_div_right", "div_self_mul_self'", "mul_div_left_comm", "mul_inv_rev", "norm_smul", "zpow_two" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_deriv_le_of_forall_mem_sphere_norm_le {c : ℂ} {R C : ℝ} {f : ℂ → F} (hR : 0 < R) (hd : diff_cont_on_cl ℂ f (ball c R)) (hC : ∀ z ∈ sphere c R, ‖f z‖ ≤ C) : ‖deriv f c‖ ≤ C / R
begin set e : F →L[ℂ] F̂ := uniform_space.completion.to_complL, have : has_deriv_at (e ∘ f) (e (deriv f c)) c, from e.has_fderiv_at.comp_has_deriv_at c (hd.differentiable_at is_open_ball $ mem_ball_self hR).has_deriv_at, calc ‖deriv f c‖ = ‖deriv (e ∘ f) c‖ : by { rw this.deriv, exact (uniform_space...
lemma
complex.norm_deriv_le_of_forall_mem_sphere_norm_le
analysis.complex
src/analysis/complex/liouville.lean
[ "analysis.complex.cauchy_integral", "analysis.calculus.fderiv_analytic", "analysis.normed_space.completion" ]
[ "deriv", "diff_cont_on_cl", "has_deriv_at", "uniform_space.completion.norm_coe", "uniform_space.completion.to_complL" ]
If `f` is complex differentiable on an open disc of radius `R > 0`, is continuous on its closure, and its values on the boundary circle of this disc are bounded from above by `C`, then the norm of its derivative at the center is at most `C / R`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
liouville_theorem_aux {f : ℂ → F} (hf : differentiable ℂ f) (hb : bounded (range f)) (z w : ℂ) : f z = f w
begin suffices : ∀ c, deriv f c = 0, from is_const_of_deriv_eq_zero hf this z w, clear z w, intro c, obtain ⟨C, C₀, hC⟩ : ∃ C > (0 : ℝ), ∀ z, ‖f z‖ ≤ C, { rcases bounded_iff_forall_norm_le.1 hb with ⟨C, hC⟩, exact ⟨max C 1, lt_max_iff.2 (or.inr zero_lt_one), λ z, (hC (f z) (mem_range_self _)).trans (l...
lemma
complex.liouville_theorem_aux
analysis.complex
src/analysis/complex/liouville.lean
[ "analysis.complex.cauchy_integral", "analysis.calculus.fderiv_analytic", "analysis.normed_space.completion" ]
[ "deriv", "differentiable", "div_div_cancel'", "div_pos", "is_const_of_deriv_eq_zero", "le_of_forall_le_of_dense", "zero_lt_one" ]
An auxiliary lemma for Liouville's theorem `differentiable.apply_eq_apply_of_bounded`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_eq_apply_of_bounded {f : E → F} (hf : differentiable ℂ f) (hb : bounded (range f)) (z w : E) : f z = f w
begin set g : ℂ → F := f ∘ (λ t : ℂ, t • (w - z) + z), suffices : g 0 = g 1, by simpa [g], apply liouville_theorem_aux, exacts [hf.comp ((differentiable_id.smul_const (w - z)).add_const z), hb.mono (range_comp_subset_range _ _)] end
lemma
differentiable.apply_eq_apply_of_bounded
analysis.complex
src/analysis/complex/liouville.lean
[ "analysis.complex.cauchy_integral", "analysis.calculus.fderiv_analytic", "analysis.normed_space.completion" ]
[ "differentiable" ]
**Liouville's theorem**: a complex differentiable bounded function `f : E → F` is a constant.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_const_forall_eq_of_bounded {f : E → F} (hf : differentiable ℂ f) (hb : bounded (range f)) : ∃ c, ∀ z, f z = c
⟨f 0, λ z, hf.apply_eq_apply_of_bounded hb _ _⟩
lemma
differentiable.exists_const_forall_eq_of_bounded
analysis.complex
src/analysis/complex/liouville.lean
[ "analysis.complex.cauchy_integral", "analysis.calculus.fderiv_analytic", "analysis.normed_space.completion" ]
[ "differentiable" ]
**Liouville's theorem**: a complex differentiable bounded function is a constant.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_eq_const_of_bounded {f : E → F} (hf : differentiable ℂ f) (hb : bounded (range f)) : ∃ c, f = const E c
(hf.exists_const_forall_eq_of_bounded hb).imp $ λ c, funext
lemma
differentiable.exists_eq_const_of_bounded
analysis.complex
src/analysis/complex/liouville.lean
[ "analysis.complex.cauchy_integral", "analysis.calculus.fderiv_analytic", "analysis.normed_space.completion" ]
[ "differentiable" ]
**Liouville's theorem**: a complex differentiable bounded function is a constant.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cderiv (r : ℝ) (f : ℂ → E) (z : ℂ) : E
(2 * π * I : ℂ)⁻¹ • ∮ w in C(z, r), ((w - z) ^ 2)⁻¹ • f w
def
complex.cderiv
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[]
A circle integral which coincides with `deriv f z` whenever one can apply the Cauchy formula for the derivative. It is useful in the proof that locally uniform limits of holomorphic functions are holomorphic, because it depends continuously on `f` for the uniform topology.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cderiv_eq_deriv (hU : is_open U) (hf : differentiable_on ℂ f U) (hr : 0 < r) (hzr : closed_ball z r ⊆ U) : cderiv r f z = deriv f z
two_pi_I_inv_smul_circle_integral_sub_sq_inv_smul_of_differentiable hU hzr hf (mem_ball_self hr)
lemma
complex.cderiv_eq_deriv
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "deriv", "differentiable_on", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_cderiv_le (hr : 0 < r) (hf : ∀ w ∈ sphere z r, ‖f w‖ ≤ M) : ‖cderiv r f z‖ ≤ M / r
begin have hM : 0 ≤ M, { obtain ⟨w, hw⟩ : (sphere z r).nonempty := normed_space.sphere_nonempty.mpr hr.le, exact (norm_nonneg _).trans (hf w hw) }, have h1 : ∀ w ∈ sphere z r, ‖((w - z) ^ 2)⁻¹ • f w‖ ≤ M / r ^ 2, { intros w hw, simp only [mem_sphere_iff_norm, norm_eq_abs] at hw, simp only [norm_smul...
lemma
complex.norm_cderiv_le
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "circle_integral.norm_integral_le_of_norm_le_const", "complex.abs_pow", "div_le_div", "inv_mul_eq_div", "le_rfl", "map_inv₀", "mul_le_mul", "norm_smul", "ring", "sq_pos_of_pos" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cderiv_sub (hr : 0 < r) (hf : continuous_on f (sphere z r)) (hg : continuous_on g (sphere z r)) : cderiv r (f - g) z = cderiv r f z - cderiv r g z
begin have h1 : continuous_on (λ (w : ℂ), ((w - z) ^ 2)⁻¹) (sphere z r), { refine ((continuous_id'.sub continuous_const).pow 2).continuous_on.inv₀ (λ w hw h, hr.ne _), rwa [mem_sphere_iff_norm, sq_eq_zero_iff.mp h, norm_zero] at hw }, simp_rw [cderiv, ← smul_sub], congr' 1, simpa only [pi.sub_apply, smul_...
lemma
complex.cderiv_sub
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "circle_integrable", "circle_integral.integral_sub", "continuous_const", "continuous_on", "continuous_on.inv₀", "smul_sub" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_cderiv_lt (hr : 0 < r) (hfM : ∀ w ∈ sphere z r, ‖f w‖ < M) (hf : continuous_on f (sphere z r)) : ‖cderiv r f z‖ < M / r
begin obtain ⟨L, hL1, hL2⟩ : ∃ L < M, ∀ w ∈ sphere z r, ‖f w‖ ≤ L, { have e1 : (sphere z r).nonempty := normed_space.sphere_nonempty.mpr hr.le, have e2 : continuous_on (λ w, ‖f w‖) (sphere z r), from continuous_norm.comp_continuous_on hf, obtain ⟨x, hx, hx'⟩ := (is_compact_sphere z r).exists_forall_ge...
lemma
complex.norm_cderiv_lt
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "continuous_on", "div_lt_div_right", "is_compact_sphere" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
norm_cderiv_sub_lt (hr : 0 < r) (hfg : ∀ w ∈ sphere z r, ‖f w - g w‖ < M) (hf : continuous_on f (sphere z r)) (hg : continuous_on g (sphere z r)) : ‖cderiv r f z - cderiv r g z‖ < M / r
cderiv_sub hr hf hg ▸ norm_cderiv_lt hr hfg (hf.sub hg)
lemma
complex.norm_cderiv_sub_lt
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_uniformly_on.cderiv (hF : tendsto_uniformly_on F f φ (cthickening δ K)) (hδ : 0 < δ) (hFn : ∀ᶠ n in φ, continuous_on (F n) (cthickening δ K)) : tendsto_uniformly_on (cderiv δ ∘ F) (cderiv δ f) φ K
begin by_cases φ = ⊥, { simp only [h, tendsto_uniformly_on, eventually_bot, implies_true_iff]}, haveI : φ.ne_bot := ne_bot_iff.2 h, have e1 : continuous_on f (cthickening δ K) := tendsto_uniformly_on.continuous_on hF hFn, rw [tendsto_uniformly_on_iff] at hF ⊢, rintro ε hε, filter_upwards [hF (ε * δ) (mul_...
lemma
complex.tendsto_uniformly_on.cderiv
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "continuous_on", "mul_div_cancel", "tendsto_uniformly_on", "tendsto_uniformly_on.continuous_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_uniformly_on_deriv_of_cthickening_subset (hf : tendsto_locally_uniformly_on F f φ U) (hF : ∀ᶠ n in φ, differentiable_on ℂ (F n) U) {δ : ℝ} (hδ: 0 < δ) (hK : is_compact K) (hU : is_open U) (hKU : cthickening δ K ⊆ U) : tendsto_uniformly_on (deriv ∘ F) (cderiv δ f) φ K
begin have h1 : ∀ᶠ n in φ, continuous_on (F n) (cthickening δ K), by filter_upwards [hF] with n h using h.continuous_on.mono hKU, have h2 : is_compact (cthickening δ K), from is_compact_of_is_closed_bounded is_closed_cthickening hK.bounded.cthickening, have h3 : tendsto_uniformly_on F f φ (cthickening δ K...
lemma
complex.tendsto_uniformly_on_deriv_of_cthickening_subset
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "continuous_on", "deriv", "differentiable_on", "is_compact", "is_open", "tendsto_locally_uniformly_on", "tendsto_locally_uniformly_on_iff_forall_is_compact", "tendsto_uniformly_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_cthickening_tendsto_uniformly_on (hf : tendsto_locally_uniformly_on F f φ U) (hF : ∀ᶠ n in φ, differentiable_on ℂ (F n) U) (hK : is_compact K) (hU : is_open U) (hKU : K ⊆ U) : ∃ δ > 0, cthickening δ K ⊆ U ∧ tendsto_uniformly_on (deriv ∘ F) (cderiv δ f) φ K
begin obtain ⟨δ, hδ, hKδ⟩ := hK.exists_cthickening_subset_open hU hKU, exact ⟨δ, hδ, hKδ, tendsto_uniformly_on_deriv_of_cthickening_subset hf hF hδ hK hU hKδ⟩ end
lemma
complex.exists_cthickening_tendsto_uniformly_on
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "deriv", "differentiable_on", "is_compact", "is_open", "tendsto_locally_uniformly_on", "tendsto_uniformly_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.tendsto_locally_uniformly_on.differentiable_on [φ.ne_bot] (hf : tendsto_locally_uniformly_on F f φ U) (hF : ∀ᶠ n in φ, differentiable_on ℂ (F n) U) (hU : is_open U) : differentiable_on ℂ f U
begin rintro x hx, obtain ⟨K, ⟨hKx, hK⟩, hKU⟩ := (compact_basis_nhds x).mem_iff.mp (hU.mem_nhds hx), obtain ⟨δ, hδ, -, h1⟩ := exists_cthickening_tendsto_uniformly_on hf hF hK hU hKU, have h2 : interior K ⊆ U := interior_subset.trans hKU, have h3 : ∀ᶠ n in φ, differentiable_on ℂ (F n) (interior K), filter_...
theorem
tendsto_locally_uniformly_on.differentiable_on
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "compact_basis_nhds", "deriv", "differentiable_at.differentiable_within_at", "differentiable_on", "differentiable_within_at", "has_deriv_at", "has_deriv_at_of_tendsto_locally_uniformly_on'", "interior", "interior_subset", "is_open", "is_open_interior", "tendsto_locally_uniformly_on" ]
A locally uniform limit of holomorphic functions on an open domain of the complex plane is holomorphic (the derivatives converge locally uniformly to that of the limit, which is proved as `tendsto_locally_uniformly_on.deriv`).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
_root_.tendsto_locally_uniformly_on.deriv (hf : tendsto_locally_uniformly_on F f φ U) (hF : ∀ᶠ n in φ, differentiable_on ℂ (F n) U) (hU : is_open U) : tendsto_locally_uniformly_on (deriv ∘ F) (deriv f) φ U
begin rw [tendsto_locally_uniformly_on_iff_forall_is_compact hU], by_cases φ = ⊥, { simp only [h, tendsto_uniformly_on, eventually_bot, implies_true_iff] }, haveI : φ.ne_bot := ne_bot_iff.2 h, rintro K hKU hK, obtain ⟨δ, hδ, hK4, h⟩ := exists_cthickening_tendsto_uniformly_on hf hF hK hU hKU, refine h.cong...
lemma
tendsto_locally_uniformly_on.deriv
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "deriv", "differentiable_on", "is_open", "tendsto_locally_uniformly_on", "tendsto_locally_uniformly_on_iff_forall_is_compact", "tendsto_uniformly_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
differentiable_on_tsum_of_summable_norm {u : ι → ℝ} (hu : summable u) (hf : ∀ (i : ι), differentiable_on ℂ (F i) U) (hU : is_open U) (hF_le : ∀ (i : ι) (w : ℂ), w ∈ U → ‖F i w‖ ≤ u i) : differentiable_on ℂ (λ w : ℂ, ∑' (i : ι), F i w) U
begin classical, have hc := (tendsto_uniformly_on_tsum hu hF_le).tendsto_locally_uniformly_on, refine hc.differentiable_on (eventually_of_forall $ λ s, _) hU, exact differentiable_on.sum (λ i hi, hf i), end
lemma
complex.differentiable_on_tsum_of_summable_norm
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "differentiable_on", "differentiable_on.sum", "is_open", "summable", "tendsto_locally_uniformly_on", "tendsto_uniformly_on_tsum" ]
If the terms in the sum `∑' (i : ι), F i` are uniformly bounded on `U` by a summable function, and each term in the sum is differentiable on `U`, then so is the sum.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_sum_deriv_of_summable_norm {u : ι → ℝ} (hu : summable u) (hf : ∀ (i : ι), differentiable_on ℂ (F i) U) (hU : is_open U) (hF_le : ∀ (i : ι) (w : ℂ), w ∈ U → ‖F i w‖ ≤ u i) (hz : z ∈ U) : has_sum (λ (i : ι), deriv (F i) z) (deriv (λ w : ℂ, ∑' (i : ι), F i w) z)
begin rw has_sum, have hc := (tendsto_uniformly_on_tsum hu hF_le).tendsto_locally_uniformly_on, convert (hc.deriv (eventually_of_forall $ λ s, differentiable_on.sum (λ i hi, hf i)) hU).tendsto_at hz using 1, ext1 s, exact (deriv_sum (λ i hi, (hf i).differentiable_at (hU.mem_nhds hz))).symm, end
lemma
complex.has_sum_deriv_of_summable_norm
analysis.complex
src/analysis/complex/locally_uniform_limit.lean
[ "analysis.complex.removable_singularity", "analysis.calculus.series" ]
[ "deriv", "deriv_sum", "differentiable_at", "differentiable_on", "differentiable_on.sum", "has_sum", "is_open", "summable", "tendsto_locally_uniformly_on", "tendsto_uniformly_on_tsum" ]
If the terms in the sum `∑' (i : ι), F i` are uniformly bounded on `U` by a summable function, then the sum of `deriv F i` at a point in `U` is the derivative of the sum.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
diff_cont_on_cl.ball_subset_image_closed_ball (h : diff_cont_on_cl ℂ f (ball z₀ r)) (hr : 0 < r) (hf : ∀ z ∈ sphere z₀ r, ε ≤ ‖f z - f z₀‖) (hz₀ : ∃ᶠ z in 𝓝 z₀, f z ≠ f z₀) : ball (f z₀) (ε / 2) ⊆ f '' closed_ball z₀ r
begin /- This is a direct application of the maximum principle. Pick `v` close to `f z₀`, and look at the function `λ z, ‖f z - v‖`: it is bounded below on the circle, and takes a small value at `z₀` so it is not constant on the disk, which implies that its infimum is equal to `0` and hence that `v` is in the r...
lemma
diff_cont_on_cl.ball_subset_image_closed_ball
analysis.complex
src/analysis/complex/open_mapping.lean
[ "analysis.analytic.isolated_zeros", "analysis.complex.cauchy_integral", "analysis.complex.abs_max" ]
[ "analytic_on", "analytic_on_const", "closure_ball", "continuous_on", "convex_ball", "diff_cont_on_cl", "dist_comm", "is_local_min", "is_preconnected", "nhds_within_le_nhds" ]
If the modulus of a holomorphic function `f` is bounded below by `ε` on a circle, then its range contains a disk of radius `ε / 2`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
analytic_at.eventually_constant_or_nhds_le_map_nhds_aux (hf : analytic_at ℂ f z₀) : (∀ᶠ z in 𝓝 z₀, f z = f z₀) ∨ (𝓝 (f z₀) ≤ map f (𝓝 z₀))
begin /- The function `f` is analytic in a neighborhood of `z₀`; by the isolated zeros principle, if `f` is not constant in a neighborhood of `z₀`, then it is nonzero, and therefore bounded below, on every small enough circle around `z₀` and then `diff_cont_on_cl.ball_subset_image_closed_ball` provides an expli...
lemma
analytic_at.eventually_constant_or_nhds_le_map_nhds_aux
analysis.complex
src/analysis/complex/open_mapping.lean
[ "analysis.analytic.isolated_zeros", "analysis.complex.cauchy_integral", "analysis.complex.abs_max" ]
[ "analytic_at", "analytic_at_const", "analytic_on", "closure_ball", "continuous_on", "diff_cont_on_cl", "half_pos", "inf_le_left", "inf_le_right", "is_compact_sphere", "is_open_analytic_at" ]
A function `f : ℂ → ℂ` which is analytic at a point `z₀` is either constant in a neighborhood of `z₀`, or behaves locally like an open function (in the sense that the image of every neighborhood of `z₀` is a neighborhood of `f z₀`, as in `is_open_map_iff_nhds_le`). For a function `f : E → ℂ` the same result holds, see ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
analytic_at.eventually_constant_or_nhds_le_map_nhds {z₀ : E} (hg : analytic_at ℂ g z₀) : (∀ᶠ z in 𝓝 z₀, g z = g z₀) ∨ (𝓝 (g z₀) ≤ map g (𝓝 z₀))
begin /- The idea of the proof is to use the one-dimensional version applied to the restriction of `g` to lines going through `z₀` (indexed by `sphere (0 : E) 1`). If the restriction is eventually constant along each of these lines, then the identity theorem implies that `g` is constant on any ball centered at ...
lemma
analytic_at.eventually_constant_or_nhds_le_map_nhds
analysis.complex
src/analysis/complex/open_mapping.lean
[ "analysis.analytic.isolated_zeros", "analysis.complex.cauchy_integral", "analysis.complex.abs_max" ]
[ "abs_norm", "analytic_at", "analytic_at.comp", "analytic_on", "analytic_on_const", "continuous", "continuous_const", "continuous_linear_map.id", "continuous_linear_map.smul_right", "convex_ball", "eq_or_ne", "is_open_analytic_at", "is_preconnected", "mul_inv_cancel", "norm_eq_zero", "n...
The *open mapping theorem* for holomorphic functions, local version: is a function `g : E → ℂ` is analytic at a point `z₀`, then either it is constant in a neighborhood of `z₀`, or it maps every neighborhood of `z₀` to a neighborhood of `z₀`. For the particular case of a holomorphic function on `ℂ`, see `analytic_at.ev...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
analytic_on.is_constant_or_is_open (hg : analytic_on ℂ g U) (hU : is_preconnected U) : (∃ w, ∀ z ∈ U, g z = w) ∨ (∀ s ⊆ U, is_open s → is_open (g '' s))
begin by_cases ∃ z₀ ∈ U, ∀ᶠ z in 𝓝 z₀, g z = g z₀, { obtain ⟨z₀, hz₀, h⟩ := h, exact or.inl ⟨g z₀, hg.eq_on_of_preconnected_of_eventually_eq analytic_on_const hU hz₀ h⟩ }, { push_neg at h, refine or.inr (λ s hs1 hs2, is_open_iff_mem_nhds.mpr _), rintro z ⟨w, hw1, rfl⟩, exact (hg w (hs1 hw1)).even...
theorem
analytic_on.is_constant_or_is_open
analysis.complex
src/analysis/complex/open_mapping.lean
[ "analysis.analytic.isolated_zeros", "analysis.complex.cauchy_integral", "analysis.complex.abs_max" ]
[ "analytic_on", "analytic_on_const", "is_open", "is_preconnected" ]
The *open mapping theorem* for holomorphic functions, global version: if a function `g : E → ℂ` is analytic on a connected set `U`, then either it is constant on `U`, or it is open on `U` (in the sense that it maps any open set contained in `U` to an open set in `ℂ`).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
det_conj_lie : (conj_lie.to_linear_equiv : ℂ →ₗ[ℝ] ℂ).det = -1
det_conj_ae
lemma
complex.det_conj_lie
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[]
The determinant of `conj_lie`, as a linear map.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
linear_equiv_det_conj_lie : conj_lie.to_linear_equiv.det = -1
linear_equiv_det_conj_ae
lemma
complex.linear_equiv_det_conj_lie
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[]
The determinant of `conj_lie`, as a linear equiv.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
re_clm_norm : ‖re_clm‖ = 1
le_antisymm (linear_map.mk_continuous_norm_le _ zero_le_one _) $ calc 1 = ‖re_clm 1‖ : by simp ... ≤ ‖re_clm‖ : unit_le_op_norm _ _ (by simp)
lemma
complex.re_clm_norm
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[ "linear_map.mk_continuous_norm_le", "zero_le_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
re_clm_nnnorm : ‖re_clm‖₊ = 1
subtype.ext re_clm_norm
lemma
complex.re_clm_nnnorm
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[ "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
im_clm_norm : ‖im_clm‖ = 1
le_antisymm (linear_map.mk_continuous_norm_le _ zero_le_one _) $ calc 1 = ‖im_clm I‖ : by simp ... ≤ ‖im_clm‖ : unit_le_op_norm _ _ (by simp)
lemma
complex.im_clm_norm
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[ "linear_map.mk_continuous_norm_le", "zero_le_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
im_clm_nnnorm : ‖im_clm‖₊ = 1
subtype.ext im_clm_norm
lemma
complex.im_clm_nnnorm
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[ "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
conj_cle_norm : ‖(conj_cle : ℂ →L[ℝ] ℂ)‖ = 1
conj_lie.to_linear_isometry.norm_to_continuous_linear_map
lemma
complex.conj_cle_norm
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
conj_cle_nnorm : ‖(conj_cle : ℂ →L[ℝ] ℂ)‖₊ = 1
subtype.ext conj_cle_norm
lemma
complex.conj_cle_nnorm
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[ "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_real_clm_norm : ‖of_real_clm‖ = 1
of_real_li.norm_to_continuous_linear_map
lemma
complex.of_real_clm_norm
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_real_clm_nnnorm : ‖of_real_clm‖₊ = 1
subtype.ext $ of_real_clm_norm
lemma
complex.of_real_clm_nnnorm
analysis.complex
src/analysis/complex/operator_norm.lean
[ "analysis.complex.basic", "analysis.normed_space.operator_norm", "data.complex.determinant" ]
[ "subtype.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_O_sub_exp_exp {a : ℝ} {f g : ℂ → E} {l : filter ℂ} {u : ℂ → ℝ} (hBf : ∃ (c < a) B, f =O[l] (λ z, expR (B * expR (c * |u z|)))) (hBg : ∃ (c < a) B, g =O[l] (λ z, expR (B * expR (c * |u z|)))) : ∃ (c < a) B, (f - g) =O[l] (λ z, expR (B * expR (c * |u z|)))
begin have : ∀ {c₁ c₂ B₁ B₂}, c₁ ≤ c₂ → 0 ≤ B₂ → B₁ ≤ B₂ → ∀ z, ‖expR (B₁ * expR (c₁ * |u z|))‖ ≤ ‖expR (B₂ * expR (c₂ * |u z|))‖, { intros c₁ c₂ B₁ B₂ hc hB₀ hB z, rw [real.norm_eq_abs, real.norm_eq_abs, real.abs_exp, real.abs_exp, real.exp_le_exp], exact mul_le_mul hB (real.exp_le_exp.2 $ mul_le_mul_o...
lemma
phragmen_lindelof.is_O_sub_exp_exp
analysis.complex
src/analysis/complex/phragmen_lindelof.lean
[ "analysis.complex.abs_max", "analysis.asymptotics.superpolynomial_decay" ]
[ "abs_nonneg", "filter", "mul_le_mul", "mul_le_mul_of_nonneg_right", "real.abs_exp", "real.exp_le_exp", "real.exp_pos", "real.norm_eq_abs" ]
An auxiliary lemma that combines two double exponential estimates into a similar estimate on the difference of the functions.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_O_sub_exp_rpow {a : ℝ} {f g : ℂ → E} {l : filter ℂ} (hBf : ∃ (c < a) B, f =O[comap complex.abs at_top ⊓ l] (λ z, expR (B * (abs z) ^ c))) (hBg : ∃ (c < a) B, g =O[comap complex.abs at_top ⊓ l] (λ z, expR (B * (abs z) ^ c))) : ∃ (c < a) B, (f - g) =O[comap complex.abs at_top ⊓ l] (λ z, expR (B * (abs z) ^ c))
begin have : ∀ {c₁ c₂ B₁ B₂ : ℝ}, c₁ ≤ c₂ → 0 ≤ B₂ → B₁ ≤ B₂ → (λ z : ℂ, expR (B₁ * (abs z) ^ c₁)) =O[comap complex.abs at_top ⊓ l] (λ z, expR (B₂ * (abs z) ^ c₂)), { have : ∀ᶠ z : ℂ in comap complex.abs at_top ⊓ l, 1 ≤ abs z, from ((eventually_ge_at_top 1).comap _).filter_mono inf_le_left, refi...
lemma
phragmen_lindelof.is_O_sub_exp_rpow
analysis.complex
src/analysis/complex/phragmen_lindelof.lean
[ "analysis.complex.abs_max", "analysis.asymptotics.superpolynomial_decay" ]
[ "complex.abs", "filter", "inf_le_left", "mul_le_mul", "one_mul", "real.abs_exp", "real.exp_le_exp", "real.norm_eq_abs", "real.rpow_le_rpow_of_exponent_le", "real.rpow_nonneg_of_nonneg" ]
An auxiliary lemma that combines two “exponential of a power” estimates into a similar estimate on the difference of the functions.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
horizontal_strip (hfd : diff_cont_on_cl ℂ f (im ⁻¹' Ioo a b)) (hB : ∃ (c < π / (b - a)) B, f =O[comap (has_abs.abs ∘ re) at_top ⊓ 𝓟 (im ⁻¹' Ioo a b)] (λ z, expR (B * expR (c * |z.re|)))) (hle_a : ∀ z : ℂ, im z = a → ‖f z‖ ≤ C) (hle_b : ∀ z, im z = b → ‖f z‖ ≤ C) (hza : a ≤ im z) (hzb : im z ≤ b) : ‖f z‖ ≤ ...
begin -- If `im z = a` or `im z = b`, then we apply `hle_a` or `hle_b`, otherwise `im z ∈ Ioo a b`. rw le_iff_eq_or_lt at hza hzb, cases hza with hza hza, { exact hle_a _ hza.symm }, cases hzb with hzb hzb, { exact hle_b _ hzb }, -- WLOG, `0 < C`. suffices : ∀ C' : ℝ, 0 < C' → (∀ w : ℂ, im w = a → ‖f w‖ ≤ C...
lemma
phragmen_lindelof.horizontal_strip
analysis.complex
src/analysis/complex/phragmen_lindelof.lean
[ "analysis.complex.abs_max", "analysis.asymptotics.superpolynomial_decay" ]
[ "abs_eq", "abs_lt", "abs_of_pos", "closure_Ioo", "continuous_const", "diff_cont_on_cl", "differentiable", "div_eq_inv_mul", "div_mul_eq_div_div", "div_pos", "exists_between", "exp", "frontier_Ioo", "frontier_subset_closure", "ge_mem_nhds", "le_iff_eq_or_lt", "le_of_forall_le_of_dense...
**Phragmen-Lindelöf principle** in a strip `U = {z : ℂ | a < im z < b}`. Let `f : ℂ → E` be a function such that * `f` is differentiable on `U` and is continuous on its closure; * `‖f z‖` is bounded from above by `A * exp(B * exp(c * |re z|))` on `U` for some `c < π / (b - a)`; * `‖f z‖` is bounded from above by a con...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_zero_on_horizontal_strip (hd : diff_cont_on_cl ℂ f (im ⁻¹' Ioo a b)) (hB : ∃ (c < π / (b - a)) B, f =O[comap (has_abs.abs ∘ re) at_top ⊓ 𝓟 (im ⁻¹' Ioo a b)] (λ z, expR (B * expR (c * |z.re|)))) (ha : ∀ z : ℂ, z.im = a → f z = 0) (hb : ∀ z : ℂ, z.im = b → f z = 0) : eq_on f 0 (im ⁻¹' Icc a b)
λ z hz, norm_le_zero_iff.1 $ horizontal_strip hd hB (λ z hz, (ha z hz).symm ▸ norm_zero.le) (λ z hz, (hb z hz).symm ▸ norm_zero.le) hz.1 hz.2
lemma
phragmen_lindelof.eq_zero_on_horizontal_strip
analysis.complex
src/analysis/complex/phragmen_lindelof.lean
[ "analysis.complex.abs_max", "analysis.asymptotics.superpolynomial_decay" ]
[ "diff_cont_on_cl" ]
**Phragmen-Lindelöf principle** in a strip `U = {z : ℂ | a < im z < b}`. Let `f : ℂ → E` be a function such that * `f` is differentiable on `U` and is continuous on its closure; * `‖f z‖` is bounded from above by `A * exp(B * exp(c * |re z|))` on `U` for some `c < π / (b - a)`; * `f z = 0` on the boundary of `U`. The...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_on_horizontal_strip {g : ℂ → E} (hdf : diff_cont_on_cl ℂ f (im ⁻¹' Ioo a b)) (hBf : ∃ (c < π / (b - a)) B, f =O[comap (has_abs.abs ∘ re) at_top ⊓ 𝓟 (im ⁻¹' Ioo a b)] (λ z, expR (B * expR (c * |z.re|)))) (hdg : diff_cont_on_cl ℂ g (im ⁻¹' Ioo a b)) (hBg : ∃ (c < π / (b - a)) B, g =O[comap (has_abs.abs ∘ re...
λ z hz, sub_eq_zero.1 (eq_zero_on_horizontal_strip (hdf.sub hdg) (is_O_sub_exp_exp hBf hBg) (λ w hw, sub_eq_zero.2 (ha w hw)) (λ w hw, sub_eq_zero.2 (hb w hw)) hz)
lemma
phragmen_lindelof.eq_on_horizontal_strip
analysis.complex
src/analysis/complex/phragmen_lindelof.lean
[ "analysis.complex.abs_max", "analysis.asymptotics.superpolynomial_decay" ]
[ "diff_cont_on_cl" ]
**Phragmen-Lindelöf principle** in a strip `U = {z : ℂ | a < im z < b}`. Let `f g : ℂ → E` be functions such that * `f` and `g` are differentiable on `U` and are continuous on its closure; * `‖f z‖` and `‖g z‖` are bounded from above by `A * exp(B * exp(c * |re z|))` on `U` for some `c < π / (b - a)`; * `f z = g z` ...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83