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analysis.calculus.fderiv_analytic

Frechet derivatives of analytic functions. #

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A function expressible as a power series at a point has a Frechet derivative there. Also the special case in terms of deriv when the domain is 1-dimensional.

theorem has_fpower_series_at.has_fderiv_at {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {p : formal_multilinear_series 𝕜 E F} {f : E F} {x : E} (h : has_fpower_series_at f p x) :
theorem has_fpower_series_at.differentiable_at {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {p : formal_multilinear_series 𝕜 E F} {f : E F} {x : E} (h : has_fpower_series_at f p x) :
theorem analytic_at.differentiable_at {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {f : E F} {x : E} :
theorem analytic_at.differentiable_within_at {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {f : E F} {x : E} {s : set E} (h : analytic_at 𝕜 f x) :
theorem has_fpower_series_at.fderiv_eq {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {p : formal_multilinear_series 𝕜 E F} {f : E F} {x : E} (h : has_fpower_series_at f p x) :
theorem analytic_on.differentiable_on {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {f : E F} {s : set E} (h : analytic_on 𝕜 f s) :
theorem has_fpower_series_on_ball.has_fderiv_at {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {p : formal_multilinear_series 𝕜 E F} {r : ennreal} {f : E F} {x : E} [complete_space F] (h : has_fpower_series_on_ball f p x r) {y : E} (hy : y‖₊ < r) :
theorem has_fpower_series_on_ball.fderiv_eq {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {p : formal_multilinear_series 𝕜 E F} {r : ennreal} {f : E F} {x : E} [complete_space F] (h : has_fpower_series_on_ball f p x r) {y : E} (hy : y‖₊ < r) :

If a function has a power series on a ball, then so does its derivative.

theorem analytic_on.fderiv {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {f : E F} {s : set E} [complete_space F] (h : analytic_on 𝕜 f s) :
analytic_on 𝕜 (fderiv 𝕜 f) s

If a function is analytic on a set s, so is its Fréchet derivative.

theorem analytic_on.iterated_fderiv {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {f : E F} {s : set E} [complete_space F] (h : analytic_on 𝕜 f s) (n : ) :
analytic_on 𝕜 (iterated_fderiv 𝕜 n f) s

If a function is analytic on a set s, so are its successive Fréchet derivative.

theorem analytic_on.cont_diff_on {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {E : Type u_2} [normed_add_comm_group E] [normed_space 𝕜 E] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {f : E F} {s : set E} [complete_space F] (h : analytic_on 𝕜 f s) {n : ℕ∞} :
cont_diff_on 𝕜 n f s

An analytic function is infinitely differentiable.

@[protected]
theorem has_fpower_series_at.has_strict_deriv_at {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {p : formal_multilinear_series 𝕜 𝕜 F} {f : 𝕜 F} {x : 𝕜} (h : has_fpower_series_at f p x) :
has_strict_deriv_at f ((p 1) (λ (_x : fin 1), 1)) x
@[protected]
theorem has_fpower_series_at.has_deriv_at {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {p : formal_multilinear_series 𝕜 𝕜 F} {f : 𝕜 F} {x : 𝕜} (h : has_fpower_series_at f p x) :
has_deriv_at f ((p 1) (λ (_x : fin 1), 1)) x
@[protected]
theorem has_fpower_series_at.deriv {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {p : formal_multilinear_series 𝕜 𝕜 F} {f : 𝕜 F} {x : 𝕜} (h : has_fpower_series_at f p x) :
deriv f x = (p 1) (λ (_x : fin 1), 1)
theorem analytic_on.deriv {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {f : 𝕜 F} {s : set 𝕜} [complete_space F] (h : analytic_on 𝕜 f s) :
analytic_on 𝕜 (deriv f) s

If a function is analytic on a set s, so is its derivative.

theorem analytic_on.iterated_deriv {𝕜 : Type u_1} [nontrivially_normed_field 𝕜] {F : Type u_3} [normed_add_comm_group F] [normed_space 𝕜 F] {f : 𝕜 F} {s : set 𝕜} [complete_space F] (h : analytic_on 𝕜 f s) (n : ) :
analytic_on 𝕜 (deriv^[n] f) s

If a function is analytic on a set s, so are its successive derivatives.