doc-next-gen

Mathlib.Analysis.Analytic.Linear

Module docstring

{"# Linear functions are analytic

In this file we prove that a ContinuousLinearMap defines an analytic function with the formal power series f x = f a + f (x - a). We also prove similar results for bilinear maps.

We deduce this fact from the stronger result that continuous linear maps are continuously polynomial, i.e., they admit a finite power series. "}

ContinuousLinearMap.fpowerSeries_radius theorem
(f : E β†’L[π•œ] F) (x : E) : (f.fpowerSeries x).radius = ∞
Full source
@[simp]
theorem fpowerSeries_radius (f : E β†’L[π•œ] F) (x : E) : (f.fpowerSeries x).radius = ∞ :=
  (f.fpowerSeries x).radius_eq_top_of_forall_image_add_eq_zero 2 fun _ => rfl
Infinite Radius of Convergence for Continuous Linear Map Power Series
Informal description
For any continuous linear map \( f \colon E \to F \) between normed spaces over a field \( \mathbb{K} \), and for any point \( x \in E \), the formal power series associated to \( f \) centered at \( x \) has an infinite radius of convergence, i.e., \(\text{radius}(f.\text{fpowerSeries}\, x) = \infty\).
ContinuousLinearMap.hasFiniteFPowerSeriesOnBall theorem
(f : E β†’L[π•œ] F) (x : E) : HasFiniteFPowerSeriesOnBall f (f.fpowerSeries x) x 2 ∞
Full source
protected theorem hasFiniteFPowerSeriesOnBall (f : E β†’L[π•œ] F) (x : E) :
    HasFiniteFPowerSeriesOnBall f (f.fpowerSeries x) x 2 ∞ where
  r_le := by simp
  r_pos := ENNReal.coe_lt_top
  hasSum := fun _ => (hasSum_nat_add_iff' 2).1 <| by
    simp [Finset.sum_range_succ, ← sub_sub, hasSum_zero, fpowerSeries]
  finite := by
    intro m hm
    match m with
    | 0 | 1 => linarith
    | n + 2 => simp [fpowerSeries]
Finite power series expansion property for continuous linear maps
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. For any point $x \in E$, the function $f$ admits a finite power series expansion on the ball of infinite radius centered at $x$, given by the formal power series $f.\text{fpowerSeries}\,x$ with all terms of degree 2 or higher vanishing.
ContinuousLinearMap.hasFPowerSeriesOnBall theorem
(f : E β†’L[π•œ] F) (x : E) : HasFPowerSeriesOnBall f (f.fpowerSeries x) x ∞
Full source
protected theorem hasFPowerSeriesOnBall (f : E β†’L[π•œ] F) (x : E) :
    HasFPowerSeriesOnBall f (f.fpowerSeries x) x ∞ :=
  (f.hasFiniteFPowerSeriesOnBall x).toHasFPowerSeriesOnBall
Power Series Expansion of Continuous Linear Maps on Infinite Balls
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. For any point $x \in E$, the function $f$ admits a power series expansion on the ball of infinite radius centered at $x$, given by the formal power series $f.\text{fpowerSeries}\,x$.
ContinuousLinearMap.hasFPowerSeriesAt theorem
(f : E β†’L[π•œ] F) (x : E) : HasFPowerSeriesAt f (f.fpowerSeries x) x
Full source
protected theorem hasFPowerSeriesAt (f : E β†’L[π•œ] F) (x : E) :
    HasFPowerSeriesAt f (f.fpowerSeries x) x :=
  ⟨∞, f.hasFPowerSeriesOnBall x⟩
Power Series Expansion of Continuous Linear Maps at a Point
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. For any point $x \in E$, the function $f$ has a power series expansion at $x$ given by the formal power series $f.\text{fpowerSeries}\,x$.
ContinuousLinearMap.cpolynomialAt theorem
(f : E β†’L[π•œ] F) (x : E) : CPolynomialAt π•œ f x
Full source
protected theorem cpolynomialAt (f : E β†’L[π•œ] F) (x : E) : CPolynomialAt π•œ f x :=
  (f.hasFiniteFPowerSeriesOnBall x).cpolynomialAt
Continuous linear maps are continuously polynomial at every point
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. Then $f$ is continuously polynomial at every point $x \in E$.
ContinuousLinearMap.analyticAt theorem
(f : E β†’L[π•œ] F) (x : E) : AnalyticAt π•œ f x
Full source
protected theorem analyticAt (f : E β†’L[π•œ] F) (x : E) : AnalyticAt π•œ f x :=
  (f.hasFPowerSeriesAt x).analyticAt
Continuous linear maps are analytic at every point
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. Then $f$ is analytic at every point $x \in E$.
ContinuousLinearMap.cpolynomialOn theorem
(f : E β†’L[π•œ] F) (s : Set E) : CPolynomialOn π•œ f s
Full source
protected theorem cpolynomialOn (f : E β†’L[π•œ] F) (s : Set E) : CPolynomialOn π•œ f s :=
  fun x _ ↦ f.cpolynomialAt x
Continuous linear maps are continuously polynomial on any subset
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. Then $f$ is continuously polynomial on any subset $s \subseteq E$, meaning that for every $x \in s$, $f$ admits a finite power series expansion around $x$.
ContinuousLinearMap.analyticOnNhd theorem
(f : E β†’L[π•œ] F) (s : Set E) : AnalyticOnNhd π•œ f s
Full source
protected theorem analyticOnNhd (f : E β†’L[π•œ] F) (s : Set E) : AnalyticOnNhd π•œ f s :=
  fun x _ ↦ f.analyticAt x
Continuous Linear Maps are Analytic on Neighborhoods of Subsets
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. Then $f$ is analytic on a neighborhood of any subset $s \subseteq E$, meaning that for every point $x \in s$, there exists a neighborhood of $x$ where $f$ admits a convergent power series expansion.
ContinuousLinearMap.analyticWithinAt theorem
(f : E β†’L[π•œ] F) (s : Set E) (x : E) : AnalyticWithinAt π•œ f s x
Full source
protected theorem analyticWithinAt (f : E β†’L[π•œ] F) (s : Set E) (x : E) : AnalyticWithinAt π•œ f s x :=
  (f.analyticAt x).analyticWithinAt
Continuous linear maps are analytic within any set at any point
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. Then for any subset $s \subseteq E$ and any point $x \in E$, the function $f$ is analytic within $s$ at $x$.
ContinuousLinearMap.analyticOn theorem
(f : E β†’L[π•œ] F) (s : Set E) : AnalyticOn π•œ f s
Full source
protected theorem analyticOn (f : E β†’L[π•œ] F) (s : Set E) : AnalyticOn π•œ f s :=
  fun x _ ↦ f.analyticWithinAt _ x
Continuous Linear Maps are Analytic on Any Subset
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear map. Then $f$ is analytic on any subset $s \subseteq E$, meaning that for every point $x \in s$, the function $f$ admits a convergent power series expansion in a neighborhood of $x$ intersected with $s$.
ContinuousLinearMap.uncurryBilinear definition
(f : E β†’L[π•œ] F β†’L[π•œ] G) : E Γ— F [Γ—2]β†’L[π•œ] G
Full source
/-- Reinterpret a bilinear map `f : E β†’L[π•œ] F β†’L[π•œ] G` as a multilinear map
`(E Γ— F) [Γ—2]β†’L[π•œ] G`. This multilinear map is the second term in the formal
multilinear series expansion of `uncurry f`. It is given by
`f.uncurryBilinear ![(x, y), (x', y')] = f x y'`. -/
def uncurryBilinear (f : E β†’L[π•œ] F β†’L[π•œ] G) : E Γ— FE Γ— F[Γ—2]β†’L[π•œ] G :=
  @ContinuousLinearMap.uncurryLeft π•œ 1 (fun _ => E Γ— F) G _ _ _ _ _ <|
    (↑(continuousMultilinearCurryFin1 π•œ (E Γ— F) G).symm : (E Γ— F β†’L[π•œ] G) β†’L[π•œ] _).comp <|
      f.bilinearComp (fst _ _ _) (snd _ _ _)
Uncurried Bilinear Map as Multilinear Map
Informal description
Given a continuous bilinear map \( f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G \), the function `uncurryBilinear` reinterprets \( f \) as a multilinear map \( (E \times F)^{[2]} \to_{L[\mathbb{K}]} G \). This multilinear map represents the second term in the formal multilinear series expansion of the uncurried version of \( f \). Specifically, it satisfies \( f.\text{uncurryBilinear} [(x, y), (x', y')] = f x y' \).
ContinuousLinearMap.uncurryBilinear_apply theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (m : Fin 2 β†’ E Γ— F) : f.uncurryBilinear m = f (m 0).1 (m 1).2
Full source
@[simp]
theorem uncurryBilinear_apply (f : E β†’L[π•œ] F β†’L[π•œ] G) (m : Fin 2 β†’ E Γ— F) :
    f.uncurryBilinear m = f (m 0).1 (m 1).2 :=
  rfl
Evaluation of Uncurried Bilinear Map
Informal description
Let $E$, $F$, and $G$ be normed spaces over a field $\mathbb{K}$, and let $f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$ be a continuous bilinear map. For any function $m : \text{Fin } 2 \to E \times F$, the evaluation of the uncurried bilinear map $f.\text{uncurryBilinear}$ at $m$ equals $f$ applied to the first component of $m(0)$ and the second component of $m(1)$, i.e., \[ f.\text{uncurryBilinear}(m) = f(m(0)_1)(m(1)_2). \]
ContinuousLinearMap.fpowerSeriesBilinear definition
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : FormalMultilinearSeries π•œ (E Γ— F) G
Full source
/-- Formal multilinear series expansion of a bilinear function `f : E β†’L[π•œ] F β†’L[π•œ] G`. -/
def fpowerSeriesBilinear (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : FormalMultilinearSeries π•œ (E Γ— F) G
  | 0 => ContinuousMultilinearMap.uncurry0 π•œ _ (f x.1 x.2)
  | 1 => (continuousMultilinearCurryFin1 π•œ (E Γ— F) G).symm (f.derivβ‚‚ x)
  | 2 => f.uncurryBilinear
  | _ => 0
Formal multilinear series expansion of a continuous bilinear map
Informal description
Given a continuous bilinear map \( f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G \) and a point \( x \in E \times F \), the formal multilinear series expansion of \( f \) at \( x \) is defined as follows: - The 0-th term is the constant term \( f(x_1, x_2) \), viewed as a 0-linear map. - The 1-st term is the derivative of \( f \) at \( x \), reinterpreted as a 1-linear map. - The 2-nd term is the uncurried bilinear map \( f \) itself, viewed as a 2-linear map. - All higher terms are zero.
ContinuousLinearMap.fpowerSeriesBilinear_apply_zero theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : fpowerSeriesBilinear f x 0 = ContinuousMultilinearMap.uncurry0 π•œ _ (f x.1 x.2)
Full source
@[simp]
theorem fpowerSeriesBilinear_apply_zero (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) :
    fpowerSeriesBilinear f x 0 = ContinuousMultilinearMap.uncurry0 π•œ _ (f x.1 x.2) :=
  rfl
Zeroth Term of Formal Multilinear Series for Continuous Bilinear Map
Informal description
For a continuous bilinear map $f \colon E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$ and a point $x = (x_1, x_2) \in E \times F$, the zeroth term of the formal multilinear series expansion of $f$ at $x$ is equal to the constant term $f(x_1, x_2)$, viewed as a 0-linear map.
ContinuousLinearMap.fpowerSeriesBilinear_apply_one theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : fpowerSeriesBilinear f x 1 = (continuousMultilinearCurryFin1 π•œ (E Γ— F) G).symm (f.derivβ‚‚ x)
Full source
@[simp]
theorem fpowerSeriesBilinear_apply_one (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) :
    fpowerSeriesBilinear f x 1 = (continuousMultilinearCurryFin1 π•œ (E Γ— F) G).symm (f.derivβ‚‚ x) :=
  rfl
First-order term of formal multilinear series expansion of a continuous bilinear map equals its derivative
Informal description
For any continuous bilinear map $f \colon E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$ and any point $x \in E \times F$, the first-order term of the formal multilinear series expansion of $f$ at $x$ is equal to the derivative of $f$ at $x$, reinterpreted as a $1$-linear map via the inverse of the continuous multilinear curry isomorphism for $1$-linear maps.
ContinuousLinearMap.fpowerSeriesBilinear_apply_two theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : fpowerSeriesBilinear f x 2 = f.uncurryBilinear
Full source
@[simp]
theorem fpowerSeriesBilinear_apply_two (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) :
    fpowerSeriesBilinear f x 2 = f.uncurryBilinear :=
  rfl
Second Term of Formal Multilinear Series for Continuous Bilinear Map Equals Uncurried Bilinear Map
Informal description
For any continuous bilinear map $f \colon E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$ and any point $x \in E \times F$, the second term of the formal multilinear series expansion of $f$ at $x$ is equal to the uncurried bilinear map $f$ interpreted as a multilinear map.
ContinuousLinearMap.fpowerSeriesBilinear_apply_add_three theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) (n) : fpowerSeriesBilinear f x (n + 3) = 0
Full source
@[simp]
theorem fpowerSeriesBilinear_apply_add_three (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) (n) :
    fpowerSeriesBilinear f x (n + 3) = 0 :=
  rfl
Vanishing of Higher Terms in Formal Multilinear Series Expansion of Bilinear Maps
Informal description
For any continuous bilinear map \( f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G \), point \( x \in E \times F \), and natural number \( n \), the \((n+3)\)-th term of the formal multilinear series expansion of \( f \) at \( x \) is zero, i.e., \( (f.\text{fpowerSeriesBilinear} \, x) \, (n + 3) = 0 \).
ContinuousLinearMap.fpowerSeriesBilinear_radius theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : (f.fpowerSeriesBilinear x).radius = ∞
Full source
@[simp]
theorem fpowerSeriesBilinear_radius (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) :
    (f.fpowerSeriesBilinear x).radius = ∞ :=
  (f.fpowerSeriesBilinear x).radius_eq_top_of_forall_image_add_eq_zero 3 fun _ => rfl
Infinite Radius of Convergence for Formal Multilinear Series of Continuous Bilinear Maps
Informal description
For any continuous bilinear map \( f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G \) and any point \( x \in E \times F \), the radius of convergence of the formal multilinear series expansion of \( f \) at \( x \) is infinite, i.e., \(\text{radius}(f.\text{fpowerSeriesBilinear} \, x) = \infty\).
ContinuousLinearMap.hasFPowerSeriesOnBall_bilinear theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : HasFPowerSeriesOnBall (fun x : E Γ— F => f x.1 x.2) (f.fpowerSeriesBilinear x) x ∞
Full source
protected theorem hasFPowerSeriesOnBall_bilinear (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) :
    HasFPowerSeriesOnBall (fun x : E Γ— F => f x.1 x.2) (f.fpowerSeriesBilinear x) x ∞ :=
  { r_le := by simp
    r_pos := ENNReal.coe_lt_top
    hasSum := fun _ =>
      (hasSum_nat_add_iff' 3).1 <| by
        simp only [Finset.sum_range_succ, Finset.sum_range_one, Prod.fst_add, Prod.snd_add,
          f.map_add_add]
        simp [fpowerSeriesBilinear, hasSum_zero] }
Power Series Expansion of Continuous Bilinear Maps with Infinite Radius of Convergence
Informal description
Let \( E \), \( F \), and \( G \) be normed spaces over a field \( \mathbb{K} \). For any continuous bilinear map \( f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G \) and any point \( x \in E \times F \), the function \( (x_1, x_2) \mapsto f(x_1)(x_2) \) has a formal power series expansion \( f.\text{fpowerSeriesBilinear} \, x \) centered at \( x \) with an infinite radius of convergence. Specifically, for all \( y \) in the ball of infinite radius centered at \( x \), the function can be expressed as: \[ f(x_1 + y_1, x_2 + y_2) = \sum_{n=0}^\infty (f.\text{fpowerSeriesBilinear} \, x)_n (y_1, y_2)^n. \] Here, the series terminates after the second term, with the 0-th term being \( f(x_1, x_2) \), the 1-st term being the derivative of \( f \) at \( x \), and the 2-nd term being the bilinear map \( f \) itself, while all higher terms vanish.
ContinuousLinearMap.hasFPowerSeriesAt_bilinear theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : HasFPowerSeriesAt (fun x : E Γ— F => f x.1 x.2) (f.fpowerSeriesBilinear x) x
Full source
protected theorem hasFPowerSeriesAt_bilinear (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) :
    HasFPowerSeriesAt (fun x : E Γ— F => f x.1 x.2) (f.fpowerSeriesBilinear x) x :=
  ⟨∞, f.hasFPowerSeriesOnBall_bilinear x⟩
Power Series Expansion of Continuous Bilinear Maps at a Point
Informal description
Let $E$, $F$, and $G$ be normed spaces over a field $\mathbb{K}$. For any continuous bilinear map $f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$ and any point $x \in E \times F$, the function $(x_1, x_2) \mapsto f(x_1)(x_2)$ has a formal power series expansion at $x$ given by $f.\text{fpowerSeriesBilinear} \, x$. Specifically, this means there exists a neighborhood of $x$ where the function can be expressed as: \[ f(x_1 + y_1, x_2 + y_2) = \sum_{n=0}^\infty (f.\text{fpowerSeriesBilinear} \, x)_n (y_1, y_2)^n \] where the series terminates after the second term (with the 0-th term being $f(x_1, x_2)$, the 1-st term being the derivative of $f$ at $x$, and the 2-nd term being $f$ itself).
ContinuousLinearMap.analyticAt_bilinear theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) : AnalyticAt π•œ (fun x : E Γ— F => f x.1 x.2) x
Full source
protected theorem analyticAt_bilinear (f : E β†’L[π•œ] F β†’L[π•œ] G) (x : E Γ— F) :
    AnalyticAt π•œ (fun x : E Γ— F => f x.1 x.2) x :=
  (f.hasFPowerSeriesAt_bilinear x).analyticAt
Analyticity of Continuous Bilinear Maps at a Point
Informal description
Let $E$, $F$, and $G$ be normed spaces over a field $\mathbb{K}$. For any continuous bilinear map $f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$ and any point $x \in E \times F$, the function $(x_1, x_2) \mapsto f(x_1)(x_2)$ is analytic at $x$.
ContinuousLinearMap.analyticWithinAt_bilinear theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (s : Set (E Γ— F)) (x : E Γ— F) : AnalyticWithinAt π•œ (fun x : E Γ— F => f x.1 x.2) s x
Full source
protected theorem analyticWithinAt_bilinear (f : E β†’L[π•œ] F β†’L[π•œ] G) (s : Set (E Γ— F)) (x : E Γ— F) :
    AnalyticWithinAt π•œ (fun x : E Γ— F => f x.1 x.2) s x :=
  (f.analyticAt_bilinear x).analyticWithinAt
Analyticity of Continuous Bilinear Maps Within a Set at a Point
Informal description
Let $E$, $F$, and $G$ be normed spaces over a field $\mathbb{K}$. For any continuous bilinear map $f : E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$, any subset $s \subseteq E \times F$, and any point $x \in E \times F$, the function $(x_1, x_2) \mapsto f(x_1)(x_2)$ is analytic within $s$ at $x$. This means there exists a neighborhood of $x$ where the function can be expressed as a convergent power series expansion within $s \cup \{x\}$.
ContinuousLinearMap.analyticOnNhd_bilinear theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (s : Set (E Γ— F)) : AnalyticOnNhd π•œ (fun x : E Γ— F => f x.1 x.2) s
Full source
protected theorem analyticOnNhd_bilinear (f : E β†’L[π•œ] F β†’L[π•œ] G) (s : Set (E Γ— F)) :
    AnalyticOnNhd π•œ (fun x : E Γ— F => f x.1 x.2) s :=
  fun x _ ↦ f.analyticAt_bilinear x
Analyticity of Continuous Bilinear Maps on a Neighborhood of a Set
Informal description
Let $E$, $F$, and $G$ be normed spaces over a field $\mathbb{K}$. For any continuous bilinear map $f \colon E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$ and any subset $s \subseteq E \times F$, the function $(x_1, x_2) \mapsto f(x_1)(x_2)$ is analytic on a neighborhood of $s$.
ContinuousLinearMap.analyticOn_bilinear theorem
(f : E β†’L[π•œ] F β†’L[π•œ] G) (s : Set (E Γ— F)) : AnalyticOn π•œ (fun x : E Γ— F => f x.1 x.2) s
Full source
protected theorem analyticOn_bilinear (f : E β†’L[π•œ] F β†’L[π•œ] G) (s : Set (E Γ— F)) :
    AnalyticOn π•œ (fun x : E Γ— F => f x.1 x.2) s :=
  (f.analyticOnNhd_bilinear s).analyticOn
Analyticity of Continuous Bilinear Maps on a Set
Informal description
Let $E$, $F$, and $G$ be normed spaces over a field $\mathbb{K}$. For any continuous bilinear map $f \colon E \to_{L[\mathbb{K}]} F \to_{L[\mathbb{K}]} G$ and any subset $s \subseteq E \times F$, the function $(x_1, x_2) \mapsto f(x_1)(x_2)$ is analytic on $s$.
analyticAt_id theorem
: AnalyticAt π•œ (id : E β†’ E) z
Full source
@[fun_prop]
lemma analyticAt_id : AnalyticAt π•œ (id : E β†’ E) z :=
  (ContinuousLinearMap.id π•œ E).analyticAt z
Identity Function is Analytic at Every Point
Informal description
The identity function $\mathrm{id} \colon E \to E$ is analytic at every point $z \in E$.
analyticWithinAt_id theorem
: AnalyticWithinAt π•œ (id : E β†’ E) s z
Full source
lemma analyticWithinAt_id : AnalyticWithinAt π•œ (id : E β†’ E) s z :=
  analyticAt_id.analyticWithinAt
Identity Function is Analytic Within Any Set at Every Point
Informal description
The identity function $\mathrm{id} \colon E \to E$ is analytic within any subset $s \subseteq E$ at every point $z \in E$.
analyticOnNhd_id theorem
: AnalyticOnNhd π•œ (fun x : E ↦ x) s
Full source
/-- `id` is entire -/
theorem analyticOnNhd_id : AnalyticOnNhd π•œ (fun x : E ↦ x) s :=
  fun _ _ ↦ analyticAt_id
Identity Function is Analytic on Neighborhood of Any Set
Informal description
The identity function $\mathrm{id} \colon E \to E$, defined by $\mathrm{id}(x) = x$, is analytic on a neighborhood of any set $s \subseteq E$.
analyticOn_id theorem
: AnalyticOn π•œ (fun x : E ↦ x) s
Full source
theorem analyticOn_id : AnalyticOn π•œ (fun x : E ↦ x) s :=
  fun _ _ ↦ analyticWithinAt_id
Analyticity of the Identity Function on Any Subset
Informal description
The identity function $\mathrm{id} \colon E \to E$, defined by $\mathrm{id}(x) = x$, is analytic on any subset $s \subseteq E$.
analyticAt_fst theorem
: AnalyticAt π•œ (fun p : E Γ— F ↦ p.fst) p
Full source
/-- `fst` is analytic -/
theorem analyticAt_fst : AnalyticAt π•œ (fun p : E Γ— F ↦ p.fst) p :=
  (ContinuousLinearMap.fst π•œ E F).analyticAt p
Analyticity of the first projection map on product spaces
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$. The projection map $\pi_1 \colon E \times F \to E$ defined by $\pi_1(x,y) = x$ is analytic at every point $p \in E \times F$.
analyticWithinAt_fst theorem
: AnalyticWithinAt π•œ (fun p : E Γ— F ↦ p.fst) t p
Full source
theorem analyticWithinAt_fst : AnalyticWithinAt π•œ (fun p : E Γ— F ↦ p.fst) t p :=
  analyticAt_fst.analyticWithinAt
Analyticity of the First Projection Within a Set
Informal description
The first projection map $\pi_1 \colon E \times F \to E$, defined by $\pi_1(x,y) = x$, is analytic within any subset $t \subseteq E \times F$ at every point $p \in E \times F$.
analyticAt_snd theorem
: AnalyticAt π•œ (fun p : E Γ— F ↦ p.snd) p
Full source
/-- `snd` is analytic -/
theorem analyticAt_snd : AnalyticAt π•œ (fun p : E Γ— F ↦ p.snd) p :=
  (ContinuousLinearMap.snd π•œ E F).analyticAt p
Analyticity of the Second Projection Function
Informal description
The second projection function $(x, y) \mapsto y$ from the product space $E \times F$ to $F$ is analytic at every point $p \in E \times F$.
analyticWithinAt_snd theorem
: AnalyticWithinAt π•œ (fun p : E Γ— F ↦ p.snd) t p
Full source
theorem analyticWithinAt_snd : AnalyticWithinAt π•œ (fun p : E Γ— F ↦ p.snd) t p :=
  analyticAt_snd.analyticWithinAt
Analyticity of Second Projection within a Set at a Point
Informal description
The second projection function $(x, y) \mapsto y$ from the product space $E \times F$ to $F$ is analytic within a set $t \subseteq E \times F$ at a point $p \in E \times F$.
analyticOnNhd_fst theorem
: AnalyticOnNhd π•œ (fun p : E Γ— F ↦ p.fst) t
Full source
/-- `fst` is entire -/
theorem analyticOnNhd_fst : AnalyticOnNhd π•œ (fun p : E Γ— F ↦ p.fst) t :=
  fun _ _ ↦ analyticAt_fst
Analyticity of the First Projection on a Neighborhood of a Set
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $t \subseteq E \times F$ be a subset. The first projection map $\pi_1 \colon E \times F \to E$ defined by $\pi_1(x,y) = x$ is analytic on a neighborhood of $t$.
analyticOn_fst theorem
: AnalyticOn π•œ (fun p : E Γ— F ↦ p.fst) t
Full source
theorem analyticOn_fst : AnalyticOn π•œ (fun p : E Γ— F ↦ p.fst) t :=
  fun _ _ ↦ analyticWithinAt_fst
Analyticity of the First Projection on a Set
Informal description
The first projection map $\pi_1 \colon E \times F \to E$, defined by $\pi_1(x,y) = x$, is analytic on the set $t \subseteq E \times F$.
analyticOnNhd_snd theorem
: AnalyticOnNhd π•œ (fun p : E Γ— F ↦ p.snd) t
Full source
/-- `snd` is entire -/
theorem analyticOnNhd_snd : AnalyticOnNhd π•œ (fun p : E Γ— F ↦ p.snd) t :=
  fun _ _ ↦ analyticAt_snd
Analyticity of Second Projection on Neighborhood of Set
Informal description
The second projection function $(x, y) \mapsto y$ from the product space $E \times F$ to $F$ is analytic on a neighborhood of the set $t \subseteq E \times F$.
analyticOn_snd theorem
: AnalyticOn π•œ (fun p : E Γ— F ↦ p.snd) t
Full source
theorem analyticOn_snd : AnalyticOn π•œ (fun p : E Γ— F ↦ p.snd) t :=
  fun _ _ ↦ analyticWithinAt_snd
Analyticity of Second Projection on Set
Informal description
The second projection function $(x, y) \mapsto y$ from the product space $E \times F$ to $F$ is analytic on the set $t \subseteq E \times F$.
ContinuousLinearEquiv.analyticAt theorem
: AnalyticAt π•œ f x
Full source
protected theorem analyticAt : AnalyticAt π•œ f x :=
  ((f : E β†’L[π•œ] F).hasFPowerSeriesAt x).analyticAt
Continuous linear equivalences are analytic
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear equivalence. Then $f$ is analytic at every point $x \in E$.
ContinuousLinearEquiv.analyticOnNhd theorem
: AnalyticOnNhd π•œ f s
Full source
protected theorem analyticOnNhd : AnalyticOnNhd π•œ f s :=
  fun x _ ↦ f.analyticAt x
Continuous Linear Equivalences are Locally Analytic
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear equivalence. Then $f$ is analytic on a neighborhood of any set $s \subseteq E$.
ContinuousLinearEquiv.analyticWithinAt theorem
(f : E β†’L[π•œ] F) (s : Set E) (x : E) : AnalyticWithinAt π•œ f s x
Full source
protected theorem analyticWithinAt (f : E β†’L[π•œ] F) (s : Set E) (x : E) : AnalyticWithinAt π•œ f s x :=
  (f.analyticAt x).analyticWithinAt
Analyticity of Continuous Linear Equivalences Within a Set at a Point
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear equivalence. For any subset $s \subseteq E$ and any point $x \in E$, the function $f$ is analytic within $s$ at $x$.
ContinuousLinearEquiv.analyticOn theorem
(f : E β†’L[π•œ] F) (s : Set E) : AnalyticOn π•œ f s
Full source
protected theorem analyticOn (f : E β†’L[π•œ] F) (s : Set E) : AnalyticOn π•œ f s :=
  fun x _ ↦ f.analyticWithinAt _ x
Continuous Linear Equivalences are Analytic on Any Subset
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a continuous linear equivalence. Then $f$ is analytic on any subset $s \subseteq E$, meaning that for every $x \in s$, there exists a neighborhood of $x$ where $f$ admits a convergent power series expansion.
LinearIsometryEquiv.analyticAt theorem
: AnalyticAt π•œ f x
Full source
protected theorem analyticAt : AnalyticAt π•œ f x :=
  ((f : E β†’L[π•œ] F).hasFPowerSeriesAt x).analyticAt
Analyticity of Linear Isometry Equivalences
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a linear isometry equivalence. Then $f$ is analytic at every point $x \in E$.
LinearIsometryEquiv.analyticOnNhd theorem
: AnalyticOnNhd π•œ f s
Full source
protected theorem analyticOnNhd : AnalyticOnNhd π•œ f s :=
  fun x _ ↦ f.analyticAt x
Analyticity of Linear Isometry Equivalences on Neighborhoods
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a linear isometry equivalence. Then $f$ is analytic on a neighborhood of any subset $s \subseteq E$, meaning that for every $x \in s$, there exists a neighborhood of $x$ where $f$ admits a convergent power series expansion.
LinearIsometryEquiv.analyticWithinAt theorem
(f : E β†’L[π•œ] F) (s : Set E) (x : E) : AnalyticWithinAt π•œ f s x
Full source
protected theorem analyticWithinAt (f : E β†’L[π•œ] F) (s : Set E) (x : E) : AnalyticWithinAt π•œ f s x :=
  (f.analyticAt x).analyticWithinAt
Linear Isometry Equivalences are Analytic Within Any Set at Every Point
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a linear isometry equivalence. For any subset $s \subseteq E$ and any point $x \in E$, the function $f$ is analytic within $s$ at $x$.
LinearIsometryEquiv.analyticOn theorem
(f : E β†’L[π•œ] F) (s : Set E) : AnalyticOn π•œ f s
Full source
protected theorem analyticOn (f : E β†’L[π•œ] F) (s : Set E) : AnalyticOn π•œ f s :=
  fun x _ ↦ f.analyticWithinAt _ x
Analyticity of Linear Isometry Equivalences on Subsets
Informal description
Let $E$ and $F$ be normed spaces over a field $\mathbb{K}$, and let $f \colon E \to F$ be a linear isometry equivalence. Then $f$ is analytic on any subset $s \subseteq E$, meaning that for every $x \in s$, the function $f$ admits a convergent power series expansion in a neighborhood of $x$ intersected with $s \cup \{x\}$.