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Mathlib.Analysis.SpecialFunctions.Complex.Analytic

Various complex special functions are analytic #

log, and cpow are analytic, since they are differentiable.

log is analytic away from nonpositive reals

theorem AnalyticAt.clog {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℂ E] {f : E → ℂ} {x : E} (fa : AnalyticAt ℂ f x) (m : f x ∈ Complex.slitPlane) :
AnalyticAt ℂ (fun (z : E) => Complex.log (f z)) x

log is analytic away from nonpositive reals

theorem AnalyticWithinAt.clog {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℂ E] {f : E → ℂ} {x : E} {s : Set E} (fa : AnalyticWithinAt ℂ f s x) (m : f x ∈ Complex.slitPlane) :
AnalyticWithinAt ℂ (fun (z : E) => Complex.log (f z)) s x
theorem AnalyticOnNhd.clog {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℂ E] {f : E → ℂ} {s : Set E} (fs : AnalyticOnNhd ℂ f s) (m : ∀ z ∈ s, f z ∈ Complex.slitPlane) :
AnalyticOnNhd ℂ (fun (z : E) => Complex.log (f z)) s

log is analytic away from nonpositive reals

theorem AnalyticOn.clog {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℂ E] {f : E → ℂ} {s : Set E} (fs : AnalyticOn ℂ f s) (m : ∀ z ∈ s, f z ∈ Complex.slitPlane) :
AnalyticOn ℂ (fun (z : E) => Complex.log (f z)) s
theorem AnalyticWithinAt.cpow {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℂ E] {f g : E → ℂ} {x : E} {s : Set E} (fa : AnalyticWithinAt ℂ f s x) (ga : AnalyticWithinAt ℂ g s x) (m : f x ∈ Complex.slitPlane) :
AnalyticWithinAt ℂ (fun (z : E) => f z ^ g z) s x

f z ^ g z is analytic if f z is not a nonpositive real

theorem AnalyticAt.cpow {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℂ E] {f g : E → ℂ} {x : E} (fa : AnalyticAt ℂ f x) (ga : AnalyticAt ℂ g x) (m : f x ∈ Complex.slitPlane) :
AnalyticAt ℂ (fun (z : E) => f z ^ g z) x

f z ^ g z is analytic if f z is not a nonpositive real

theorem AnalyticOn.cpow {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℂ E] {f g : E → ℂ} {s : Set E} (fs : AnalyticOn ℂ f s) (gs : AnalyticOn ℂ g s) (m : ∀ z ∈ s, f z ∈ Complex.slitPlane) :
AnalyticOn ℂ (fun (z : E) => f z ^ g z) s

f z ^ g z is analytic if f z avoids nonpositive reals

theorem AnalyticOnNhd.cpow {E : Type u_1} [NormedAddCommGroup E] [NormedSpace ℂ E] {f g : E → ℂ} {s : Set E} (fs : AnalyticOnNhd ℂ f s) (gs : AnalyticOnNhd ℂ g s) (m : ∀ z ∈ s, f z ∈ Complex.slitPlane) :
AnalyticOnNhd ℂ (fun (z : E) => f z ^ g z) s

f z ^ g z is analytic if f z avoids nonpositive reals

theorem AnalyticAt.re_ofReal {f : ℂ → ℂ} {x : ℝ} (hf : AnalyticAt ℂ f ↑x) :
AnalyticAt ℝ (fun (x : ℝ) => (f ↑x).re) x
theorem AnalyticAt.im_ofReal {f : ℂ → ℂ} {x : ℝ} (hf : AnalyticAt ℂ f ↑x) :
AnalyticAt ℝ (fun (x : ℝ) => (f ↑x).im) x
theorem AnalyticWithinAt.re_ofReal {f : ℂ → ℂ} {s : Set ℝ} {x : ℝ} (hf : AnalyticWithinAt ℂ f (Complex.ofReal '' s) ↑x) :
AnalyticWithinAt ℝ (fun (x : ℝ) => (f ↑x).re) s x
theorem AnalyticWithinAt.im_ofReal {f : ℂ → ℂ} {s : Set ℝ} {x : ℝ} (hf : AnalyticWithinAt ℂ f (Complex.ofReal '' s) ↑x) :
AnalyticWithinAt ℝ (fun (x : ℝ) => (f ↑x).im) s x
theorem AnalyticOn.re_ofReal {f : ℂ → ℂ} {s : Set ℝ} (hf : AnalyticOn ℂ f (Complex.ofReal '' s)) :
AnalyticOn ℝ (fun (x : ℝ) => (f ↑x).re) s
theorem AnalyticOn.im_ofReal {f : ℂ → ℂ} {s : Set ℝ} (hf : AnalyticOn ℂ f (Complex.ofReal '' s)) :
AnalyticOn ℝ (fun (x : ℝ) => (f ↑x).im) s
theorem AnalyticOnNhd.re_ofReal {f : ℂ → ℂ} {s : Set ℝ} (hf : AnalyticOnNhd ℂ f (Complex.ofReal '' s)) :
AnalyticOnNhd ℝ (fun (x : ℝ) => (f ↑x).re) s
theorem AnalyticOnNhd.im_ofReal {f : ℂ → ℂ} {s : Set ℝ} (hf : AnalyticOnNhd ℂ f (Complex.ofReal '' s)) :
AnalyticOnNhd ℝ (fun (x : ℝ) => (f ↑x).im) s
theorem analyticAt_log {x : ℝ} (hx : 0 < x) :
theorem AnalyticAt.log {f : ℝ → ℝ} {x : ℝ} (fa : AnalyticAt ℝ f x) (m : 0 < f x) :
AnalyticAt ℝ (fun (z : ℝ) => Real.log (f z)) x
theorem AnalyticWithinAt.log {f : ℝ → ℝ} {s : Set ℝ} {x : ℝ} (fa : AnalyticWithinAt ℝ f s x) (m : 0 < f x) :
AnalyticWithinAt ℝ (fun (z : ℝ) => Real.log (f z)) s x
theorem AnalyticOnNhd.log {f : ℝ → ℝ} {s : Set ℝ} (fs : AnalyticOnNhd ℝ f s) (m : ∀ x ∈ s, 0 < f x) :
AnalyticOnNhd ℝ (fun (z : ℝ) => Real.log (f z)) s
theorem AnalyticOn.log {f : ℝ → ℝ} {s : Set ℝ} (fs : AnalyticOn ℝ f s) (m : ∀ x ∈ s, 0 < f x) :
AnalyticOn ℝ (fun (z : ℝ) => Real.log (f z)) s
theorem iteratedDeriv_succ_log {n : ℕ} {x : ℂ} (hx : x ∈ Complex.slitPlane) :
iteratedDeriv (n + 1) Complex.log x = (-1) ^ n * ↑n.factorial * x ^ (-↑n - 1)