mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: s x y : ℝ
hx₀ : 0 < x
hx₁ : x < 1 / (1 + s ^ 2)
hy : |y| < s * x
⊢ (1 - x) ^ 2 + |y| ^ 2 ≤ (1 - x) ^ 2 + (s * x) ^ 2

Tactic:
gcongr

Goal state after:
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: s x y : ℝ
hx₀ : 0 < x
hx₁ : x < 1 / (1 + s ^ 2)
hy : |y| < s * x
⊢ √(1 - 2 * x + (1 + s ^ 2) * x * x) ≤ √(1 - 2 * x + (1 + s ^ 2) * (1 / (1 + s ^ 2)) * x)

Tactic:
gcongr

Goal state after:
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: s x y : ℝ
hx₀ : 0 < x
hx₁ : x < 1 / (1 + s ^ 2)
hy : |y| < s * x
H : √((1 - x) ^ 2 + y ^ 2) ≤ 1 - x / 2
⊢ √(x ^ 2 + |y| ^ 2) ≤ √(x ^ 2 + (s * x) ^ 2)

Tactic:
gcongr

Goal state after:
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: s x y : ℝ
hx₀ : 0 < x
hx₁ : x < 1 / (1 + s ^ 2)
hy : |y| < s * x
H : √((1 - x) ^ 2 + y ^ 2) ≤ 1 - x / 2
⊢ 2 * √(1 + s ^ 2) * (x / 2) < (2 * √(1 + s ^ 2) + 1) * (x / 2)

Tactic:
gcongr

Goal state after:
case hbc
s x y : ℝ
hx₀ : 0 < x
hx₁ : x < 1 / (1 + s ^ 2)
hy : |y| < s * x
H : √((1 - x) ^ 2 + y ^ 2) ≤ 1 - x / 2
⊢ 2 * √(1 + s ^ 2) < 2 * √(1 + s ^ 2) + 1
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: s x y : ℝ
hx₀ : 0 < x
hx₁ : x < 1 / (1 + s ^ 2)
hy : |y| < s * x
H : √((1 - x) ^ 2 + y ^ 2) ≤ 1 - x / 2
⊢ (2 * √(1 + s ^ 2) + 1) * (x / 2) ≤ (2 * √(1 + s ^ 2) + 1) * (1 - √((1 - x) ^ 2 + y ^ 2))

Tactic:
gcongr

Goal state after:
case hbc
s x y : ℝ
hx₀ : 0 < x
hx₁ : x < 1 / (1 + s ^ 2)
hy : |y| < s * x
H : √((1 - x) ^ 2 + y ^ 2) ≤ 1 - x / 2
⊢ x / 2 ≤ 1 - √((1 - x) ^ 2 + y ^ 2)
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
z : ℂ
hz : ‖z‖ < 1
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
k :
  Tendsto (fun n ↦ (1 - z) * ∑ j ∈ range n, (∑ k ∈ range n, f k - ∑ k ∈ range (j + 1), f k) * z ^ j) atTop
    (𝓝 (l - ∑' (i : ℕ), f i * z ^ i))
this : Tendsto (fun n ↦ (l - s n) * ∑ i ∈ range n, z ^ i) atTop (𝓝 0)
⊢ Tendsto (fun n ↦ (1 - z) * ∑ i ∈ range n, (l - ∑ j ∈ range (i + 1), f j) * z ^ i) atTop
    (𝓝 (l - ∑' (n : ℕ), f n * z ^ n))

Tactic:
simp_rw [mul_sum] at this

Goal state after:
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
z : ℂ
hz : ‖z‖ < 1
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
k :
  Tendsto (fun n ↦ (1 - z) * ∑ j ∈ range n, (∑ k ∈ range n, f k - ∑ k ∈ range (j + 1), f k) * z ^ j) atTop
    (𝓝 (l - ∑' (i : ℕ), f i * z ^ i))
this : Tendsto (fun n ↦ ∑ i ∈ range n, (l - s n) * z ^ i) atTop (𝓝 0)
⊢ Tendsto (fun n ↦ (1 - z) * ∑ i ∈ range n, (l - ∑ j ∈ range (i + 1), f j) * z ^ i) atTop
    (𝓝 (l - ∑' (n : ℕ), f n * z ^ n))
Module: Mathlib.Analysis.Convex.StrictConvexSpace

Goal state before:
pp: E : Type u_2
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
h : ∀ (x y : E), ‖x‖ = 1 → ‖y‖ = 1 → x ≠ y → ∃ a b, a + b = 1 ∧ ‖a • x + b • y‖ < 1
x : E
hx : x ∈ sphere 0 1
y : E
hy : y ∈ sphere 0 1
hne : x ≠ y
⊢ ∃ c, (AffineMap.lineMap x y) c ∈ interior (closedBall 0 1)

Tactic:
mem_sphere_zero_iff_norm

Goal state after:
E : Type u_2
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
h : ∀ (x y : E), ‖x‖ = 1 → ‖y‖ = 1 → x ≠ y → ∃ a b, a + b = 1 ∧ ‖a • x + b • y‖ < 1
x : E
hx : ‖x‖ = 1
y : E
hy : ‖y‖ = 1
hne : x ≠ y
⊢ ∃ c, (AffineMap.lineMap x y) c ∈ interior (closedBall 0 1)
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
z : ℂ
hz : ‖z‖ < 1
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
k :
  Tendsto (fun n ↦ (1 - z) * ∑ j ∈ range n, (∑ k ∈ range n, f k - ∑ k ∈ range (j + 1), f k) * z ^ j) atTop
    (𝓝 (l - ∑' (i : ℕ), f i * z ^ i))
this :
  Tendsto
    (fun x ↦
      (1 - z) * ∑ i ∈ range x, (l - s x) * z ^ i +
        (1 - z) * ∑ j ∈ range x, (∑ k ∈ range x, f k - ∑ k ∈ range (j + 1), f k) * z ^ j)
    atTop (𝓝 ((1 - z) * 0 + (l - ∑' (i : ℕ), f i * z ^ i)))
n : ℕ
| (1 - z) * ∑ i ∈ range n, (l - s n) * z ^ i +
    (1 - z) * ∑ j ∈ range n, (∑ k ∈ range n, f k - ∑ k ∈ range (j + 1), f k) * z ^ j

Tactic:
← mul_add,

Goal state after:
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
z : ℂ
hz : ‖z‖ < 1
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
k :
  Tendsto (fun n ↦ (1 - z) * ∑ j ∈ range n, (∑ k ∈ range n, f k - ∑ k ∈ range (j + 1), f k) * z ^ j) atTop
    (𝓝 (l - ∑' (i : ℕ), f i * z ^ i))
this :
  Tendsto
    (fun x ↦
      (1 - z) * ∑ i ∈ range x, (l - s x) * z ^ i +
        (1 - z) * ∑ j ∈ range x, (∑ k ∈ range x, f k - ∑ k ∈ range (j + 1), f k) * z ^ j)
    atTop (𝓝 ((1 - z) * 0 + (l - ∑' (i : ℕ), f i * z ^ i)))
n : ℕ
| (1 - z) * (∑ i ∈ range n, (l - s n) * z ^ i + ∑ j ∈ range n, (∑ k ∈ range n, f k - ∑ k ∈ range (j + 1), f k) * z ^ j)
Module: Mathlib.Analysis.Convex.StrictConvexSpace

Goal state before:
pp: E : Type u_2
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
h : ∀ (x y : E), ‖x‖ = 1 → ‖y‖ = 1 → ‖x + y‖ = 2 → SameRay ℝ x y
x : E
hx : x ∈ sphere 0 1
y : E
hy : y ∈ sphere 0 1
h₂ : ‖x + y‖ = 2
⊢ x = y

Tactic:
mem_sphere_zero_iff_norm

Goal state after:
E : Type u_2
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
h : ∀ (x y : E), ‖x‖ = 1 → ‖y‖ = 1 → ‖x + y‖ = 2 → SameRay ℝ x y
x : E
hx : ‖x‖ = 1
y : E
hy : ‖y‖ = 1
h₂ : ‖x + y‖ = 2
⊢ x = y
Module: Mathlib.Analysis.Convex.StrictConvexSpace

Goal state before:
pp: E : Type u_2
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : StrictConvexSpace ℝ E
x y z : E
a b r : ℝ
hx : x ∈ closedBall z r
hy : y ∈ closedBall z r
hne : x ≠ y
ha : 0 < a
hb : 0 < b
hab : a + b = 1
⊢ a • x + b • y ∈ ball z r

Tactic:
rcases eq_or_ne r 0 with (rfl | hr)

Goal state after:
case inl
E : Type u_2
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : StrictConvexSpace ℝ E
x y z : E
a b : ℝ
hne : x ≠ y
ha : 0 < a
hb : 0 < b
hab : a + b = 1
hx : x ∈ closedBall z 0
hy : y ∈ closedBall z 0
⊢ a • x + b • y ∈ ball z 0

case inr
E : Type u_2
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : StrictConvexSpace ℝ E
x y z : E
a b r : ℝ
hx : x ∈ closedBall z r
hy : y ∈ closedBall z r
hne : x ≠ y
ha : 0 < a
hb : 0 < b
hab : a + b = 1
hr : r ≠ 0
⊢ a • x + b • y ∈ ball z r
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
z : ℂ
hz : ‖z‖ < 1
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
k :
  Tendsto (fun n ↦ (1 - z) * ∑ j ∈ range n, (∑ k ∈ range n, f k - ∑ k ∈ range (j + 1), f k) * z ^ j) atTop
    (𝓝 (l - ∑' (i : ℕ), f i * z ^ i))
n : ℕ
| ∑ i ∈ range n, z ^ i

Tactic:
geom_sum_eq (by contrapose! hz; simp [hz]),

Goal state after:
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
z : ℂ
hz : ‖z‖ < 1
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
k :
  Tendsto (fun n ↦ (1 - z) * ∑ j ∈ range n, (∑ k ∈ range n, f k - ∑ k ∈ range (j + 1), f k) * z ^ j) atTop
    (𝓝 (l - ∑' (i : ℕ), f i * z ^ i))
n : ℕ
| (z ^ n - 1) / (z - 1)
Module: Mathlib.Analysis.InnerProductSpace.Convex

Goal state before:
pp: case refine_2
𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁴ : RCLike 𝕜
inst✝³ : SeminormedAddCommGroup E
inst✝² : InnerProductSpace 𝕜 E
inst✝¹ : SeminormedAddCommGroup F
inst✝ : InnerProductSpace ℝ F
ε : ℝ
hε : 0 < ε
x : F
hx : ‖x‖ = 1
y : F
hy : ‖y‖ = 1
hxy : ε ≤ ‖x - y‖
⊢ 4 - ‖x - y‖ ^ 2 ≤ 4 - ε ^ 2

Tactic:
gcongr

Goal state after:
Module: Mathlib.Analysis.Convex.Uniform

Goal state before:
pp: E : Type u_1
inst✝² : SeminormedAddCommGroup E
inst✝¹ : UniformConvexSpace E
ε : ℝ
inst✝ : NormedSpace ℝ E
hε : 0 < ε
hε' : 0 < ε / 3
δ : ℝ
hδ : 0 < δ
h : ∀ ⦃x : E⦄, ‖x‖ = 1 → ∀ ⦃y : E⦄, ‖y‖ = 1 → ε / 3 ≤ ‖x - y‖ → ‖x + y‖ ≤ 2 - δ
δ' : ℝ := min (1 / 2) (min (ε / 3) (δ / 3))
x : E
hx : ‖x‖ ≤ 1
y : E
hy : ‖y‖ ≤ 1
hxy : ε ≤ ‖x - y‖
hx' : 1 - δ' < ‖x‖
hy' : 1 - δ' < ‖y‖
hδ' : 0 < 1 - δ'
h₁ : ∀ (z : E), 1 - δ' < ‖z‖ → ‖‖z‖⁻¹ • z‖ = 1
h₂ : ∀ (z : E), ‖z‖ ≤ 1 → 1 - δ' ≤ ‖z‖ → ‖‖z‖⁻¹ • z - z‖ ≤ δ'
x' : E := ‖x‖⁻¹ • x
y' : E := ‖y‖⁻¹ • y
⊢ ε - (ε / 3 + ε / 3) ≤ ‖x - y‖ - (‖x' - x‖ + ‖y' - y‖)

Tactic:
gcongr

Goal state after:
case h₁
E : Type u_1
inst✝² : SeminormedAddCommGroup E
inst✝¹ : UniformConvexSpace E
ε : ℝ
inst✝ : NormedSpace ℝ E
hε : 0 < ε
hε' : 0 < ε / 3
δ : ℝ
hδ : 0 < δ
h : ∀ ⦃x : E⦄, ‖x‖ = 1 → ∀ ⦃y : E⦄, ‖y‖ = 1 → ε / 3 ≤ ‖x - y‖ → ‖x + y‖ ≤ 2 - δ
δ' : ℝ := ⋯
x : E
hx : ‖x‖ ≤ 1
y : E
hy : ‖y‖ ≤ 1
hxy : ε ≤ ‖x - y‖
hx' : 1 - δ' < ‖x‖
hy' : 1 - δ' < ‖y‖
hδ' : 0 < 1 - δ'
h₁ : ∀ (z : E), 1 - δ' < ‖z‖ → ‖‖z‖⁻¹ • z‖ = 1
h₂ : ∀ (z : E), ‖z‖ ≤ 1 → 1 - δ' ≤ ‖z‖ → ‖‖z‖⁻¹ • z - z‖ ≤ δ'
x' : E := ⋯
y' : E := ⋯
⊢ ‖x' - x‖ ≤ ε / 3

case h₂
E : Type u_1
inst✝² : SeminormedAddCommGroup E
inst✝¹ : UniformConvexSpace E
ε : ℝ
inst✝ : NormedSpace ℝ E
hε : 0 < ε
hε' : 0 < ε / 3
δ : ℝ
hδ : 0 < δ
h : ∀ ⦃x : E⦄, ‖x‖ = 1 → ∀ ⦃y : E⦄, ‖y‖ = 1 → ε / 3 ≤ ‖x - y‖ → ‖x + y‖ ≤ 2 - δ
δ' : ℝ := ⋯
x : E
hx : ‖x‖ ≤ 1
y : E
hy : ‖y‖ ≤ 1
hxy : ε ≤ ‖x - y‖
hx' : 1 - δ' < ‖x‖
hy' : 1 - δ' < ‖y‖
hδ' : 0 < 1 - δ'
h₁ : ∀ (z : E), 1 - δ' < ‖z‖ → ‖‖z‖⁻¹ • z‖ = 1
h₂ : ∀ (z : E), ‖z‖ ≤ 1 → 1 - δ' ≤ ‖z‖ → ‖‖z‖⁻¹ • z - z‖ ≤ δ'
x' : E := ⋯
y' : E := ⋯
⊢ ‖y' - y‖ ≤ ε / 3
Module: Mathlib.Analysis.Convex.Uniform

Goal state before:
pp: E : Type u_1
inst✝² : SeminormedAddCommGroup E
inst✝¹ : UniformConvexSpace E
ε : ℝ
inst✝ : NormedSpace ℝ E
hε : 0 < ε
hε' : 0 < ε / 3
δ : ℝ
hδ : 0 < δ
h : ∀ ⦃x : E⦄, ‖x‖ = 1 → ∀ ⦃y : E⦄, ‖y‖ = 1 → ε / 3 ≤ ‖x - y‖ → ‖x + y‖ ≤ 2 - δ
δ' : ℝ := min (1 / 2) (min (ε / 3) (δ / 3))
x : E
hx : ‖x‖ ≤ 1
y : E
hy : ‖y‖ ≤ 1
hxy : ε ≤ ‖x - y‖
hx' : 1 - δ' < ‖x‖
hy' : 1 - δ' < ‖y‖
hδ' : 0 < 1 - δ'
h₁ : ∀ (z : E), 1 - δ' < ‖z‖ → ‖‖z‖⁻¹ • z‖ = 1
h₂ : ∀ (z : E), ‖z‖ ≤ 1 → 1 - δ' ≤ ‖z‖ → ‖‖z‖⁻¹ • z - z‖ ≤ δ'
x' : E := ‖x‖⁻¹ • x
y' : E := ‖y‖⁻¹ • y
hxy' : ε / 3 ≤ ‖x' - y'‖
⊢ ‖x' + y'‖ + ‖x' - x‖ + ‖y' - y‖ ≤ 2 - δ + δ' + δ'

Tactic:
gcongr

Goal state after:
case h₁
E : Type u_1
inst✝² : SeminormedAddCommGroup E
inst✝¹ : UniformConvexSpace E
ε : ℝ
inst✝ : NormedSpace ℝ E
hε : 0 < ε
hε' : 0 < ε / 3
δ : ℝ
hδ : 0 < δ
h : ∀ ⦃x : E⦄, ‖x‖ = 1 → ∀ ⦃y : E⦄, ‖y‖ = 1 → ε / 3 ≤ ‖x - y‖ → ‖x + y‖ ≤ 2 - δ
δ' : ℝ := ⋯
x : E
hx : ‖x‖ ≤ 1
y : E
hy : ‖y‖ ≤ 1
hxy : ε ≤ ‖x - y‖
hx' : 1 - δ' < ‖x‖
hy' : 1 - δ' < ‖y‖
hδ' : 0 < 1 - δ'
h₁ : ∀ (z : E), 1 - δ' < ‖z‖ → ‖‖z‖⁻¹ • z‖ = 1
h₂ : ∀ (z : E), ‖z‖ ≤ 1 → 1 - δ' ≤ ‖z‖ → ‖‖z‖⁻¹ • z - z‖ ≤ δ'
x' : E := ⋯
y' : E := ⋯
hxy' : ε / 3 ≤ ‖x' - y'‖
⊢ ‖x' + y'‖ ≤ 2 - δ

case h₂
E : Type u_1
inst✝² : SeminormedAddCommGroup E
inst✝¹ : UniformConvexSpace E
ε : ℝ
inst✝ : NormedSpace ℝ E
hε : 0 < ε
hε' : 0 < ε / 3
δ : ℝ
hδ : 0 < δ
h : ∀ ⦃x : E⦄, ‖x‖ = 1 → ∀ ⦃y : E⦄, ‖y‖ = 1 → ε / 3 ≤ ‖x - y‖ → ‖x + y‖ ≤ 2 - δ
δ' : ℝ := ⋯
x : E
hx : ‖x‖ ≤ 1
y : E
hy : ‖y‖ ≤ 1
hxy : ε ≤ ‖x - y‖
hx' : 1 - δ' < ‖x‖
hy' : 1 - δ' < ‖y‖
hδ' : 0 < 1 - δ'
h₁ : ∀ (z : E), 1 - δ' < ‖z‖ → ‖‖z‖⁻¹ • z‖ = 1
h₂ : ∀ (z : E), ‖z‖ ≤ 1 → 1 - δ' ≤ ‖z‖ → ‖‖z‖⁻¹ • z - z‖ ≤ δ'
x' : E := ⋯
y' : E := ⋯
hxy' : ε / 3 ≤ ‖x' - y'‖
⊢ ‖x' - x‖ ≤ δ'

case h₂
E : Type u_1
inst✝² : SeminormedAddCommGroup E
inst✝¹ : UniformConvexSpace E
ε : ℝ
inst✝ : NormedSpace ℝ E
hε : 0 < ε
hε' : 0 < ε / 3
δ : ℝ
hδ : 0 < δ
h : ∀ ⦃x : E⦄, ‖x‖ = 1 → ∀ ⦃y : E⦄, ‖y‖ = 1 → ε / 3 ≤ ‖x - y‖ → ‖x + y‖ ≤ 2 - δ
δ' : ℝ := ⋯
x : E
hx : ‖x‖ ≤ 1
y : E
hy : ‖y‖ ≤ 1
hxy : ε ≤ ‖x - y‖
hx' : 1 - δ' < ‖x‖
hy' : 1 - δ' < ‖y‖
hδ' : 0 < 1 - δ'
h₁ : ∀ (z : E), 1 - δ' < ‖z‖ → ‖‖z‖⁻¹ • z‖ = 1
h₂ : ∀ (z : E), ‖z‖ ≤ 1 → 1 - δ' ≤ ‖z‖ → ‖‖z‖⁻¹ • z - z‖ ≤ δ'
x' : E := ⋯
y' : E := ⋯
hxy' : ε / 3 ≤ ‖x' - y'‖
⊢ ‖y' - y‖ ≤ δ'
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
⊢ ‖(1 - z) * ∑ i ∈ range (max B₁ B₂), (l - s (i + 1)) * z ^ i‖ =
    ‖(1 - z) * ∑ i ∈ range B₁, (l - s (i + 1)) * z ^ i + (1 - z) * ∑ i ∈ Ico B₁ (max B₁ B₂), (l - s (i + 1)) * z ^ i‖

Tactic:
← mul_add,

Goal state after:
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
⊢ ‖(1 - z) * ∑ i ∈ range (max B₁ B₂), (l - s (i + 1)) * z ^ i‖ =
    ‖(1 - z) * (∑ i ∈ range B₁, (l - s (i + 1)) * z ^ i + ∑ i ∈ Ico B₁ (max B₁ B₂), (l - s (i + 1)) * z ^ i)‖
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
⊢ ‖1 - z‖ * ‖∑ i ∈ range B₁, (l - s (i + 1)) * z ^ i‖ + ‖1 - z‖ * ‖∑ i ∈ Ico B₁ (max B₁ B₂), (l - s (i + 1)) * z ^ i‖ ≤
    ‖1 - z‖ * ∑ i ∈ range B₁, ‖l - s (i + 1)‖ * ‖z‖ ^ i + ‖1 - z‖ * ∑ i ∈ Ico B₁ (max B₁ B₂), ‖l - s (i + 1)‖ * ‖z‖ ^ i

Tactic:
gcongr

Goal state after:
case hbc
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := ⋯
g : ℂ → ℂ := ⋯
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ⋯
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
⊢ ‖∑ i ∈ range B₁, (l - s (i + 1)) * z ^ i‖ ≤ ∑ i ∈ range B₁, ‖l - s (i + 1)‖ * ‖z‖ ^ i

case hbc
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := ⋯
g : ℂ → ℂ := ⋯
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ⋯
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
⊢ ‖∑ i ∈ Ico B₁ (max B₁ B₂), (l - s (i + 1)) * z ^ i‖ ≤ ∑ i ∈ Ico B₁ (max B₁ B₂), ‖l - s (i + 1)‖ * ‖z‖ ^ i
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
⊢ ‖1 - z‖ * ∑ i ∈ range B₁, ‖l - s (i + 1)‖ * ‖z‖ ^ i ≤ ‖1 - z‖ * ∑ i ∈ range B₁, ‖l - s (i + 1)‖

Tactic:
gcongr

Goal state after:
case h
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
i : ℕ
a✝ : i ∈ range B₁
⊢ ‖l - s (i + 1)‖ * ‖z‖ ^ i ≤ ‖l - s (i + 1)‖
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: case h
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
i : ℕ
a✝ : i ∈ range B₁
⊢ ‖l - s (i + 1)‖ * ‖z‖ ^ i ≤ ‖l - s (i + 1)‖ * 1

Tactic:
gcongr

Goal state after:
case hbc
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := ⋯
g : ℂ → ℂ := ⋯
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ⋯
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
i : ℕ
a✝ : i ∈ range B₁
⊢ ‖z‖ ^ i ≤ 1
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
⊢ ‖1 - z‖ * ∑ i ∈ range B₁, ‖l - s (i + 1)‖ ≤ ‖1 - z‖ * (F + 1)

Tactic:
gcongr

Goal state after:
case hbc
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := ⋯
g : ℂ → ℂ := ⋯
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ⋯
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
⊢ ∑ i ∈ range B₁, ‖l - s (i + 1)‖ ≤ F + 1
Module: Mathlib.Analysis.Convex.SpecificFunctions.Deriv

Goal state before:
pp: ⊢ StrictConcaveOn ℝ (Icc 0 π) sin

Tactic:
apply strictConcaveOn_of_deriv2_neg (convex_Icc _ _) continuousOn_sin fun x hx => ?_
  rw [interior_Icc] at hx
  simp [sin_pos_of_mem_Ioo hx]

Goal state after:
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
S₁ : ‖1 - z‖ * ∑ i ∈ range B₁, ‖l - s (i + 1)‖ * ‖z‖ ^ i < ε / 4
⊢ ‖1 - z‖ * (ε / 4 / M) * ∑ i ∈ Ico B₁ (max B₁ B₂), ‖z‖ ^ i ≤ ‖1 - z‖ * (ε / 4 / M) * ∑' (i : ℕ), ‖z‖ ^ i

Tactic:
gcongr

Goal state after:
case hbc
f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := ⋯
g : ℂ → ℂ := ⋯
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ⋯
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
S₁ : ‖1 - z‖ * ∑ i ∈ range B₁, ‖l - s (i + 1)‖ * ‖z‖ ^ i < ε / 4
⊢ ∑ i ∈ Ico B₁ (max B₁ B₂), ‖z‖ ^ i ≤ ∑' (i : ℕ), ‖z‖ ^ i
Module: Mathlib.Analysis.SpecialFunctions.Trigonometric.Complex

Goal state before:
pp: case inr
k l : ℤ
⊢ tan ((2 * ↑k + 1) * ↑π / 2 + (2 * ↑l + 1) * ↑π / 2) =
    (tan ((2 * ↑k + 1) * ↑π / 2) + tan ((2 * ↑l + 1) * ↑π / 2)) /
      (1 - tan ((2 * ↑k + 1) * ↑π / 2) * tan ((2 * ↑l + 1) * ↑π / 2))

Tactic:
· have t := tan_int_mul_pi_div_two
    obtain ⟨hx, hy, hxy⟩ := t (2 * k + 1), t (2 * l + 1), t (2 * k + 1 + (2 * l + 1))
    simp only [Int.cast_add, Int.cast_two, Int.cast_mul, Int.cast_one] at hx hy hxy
    rw [hx, hy, add_zero, zero_div, mul_div_assoc, mul_div_assoc, ←
      add_mul (2 * (k : ℂ) + 1) (2 * l + 1) (π / 2), ← mul_div_assoc, hxy]

Goal state after:
Module: Mathlib.Analysis.Complex.AbsMax

Goal state before:
pp: E : Type u
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℂ E
F : Type v
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℂ F
f : E → F
U : Set E
c : E
hc : IsPreconnected U
ho : IsOpen[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] U
hd : DifferentiableOn ℂ f U
hcU : c ∈ U
hm : IsMaxOn (norm ∘ f) U c
⊢ EqOn (norm ∘ f) (Function.const E ‖f c‖) U

Tactic:
set V := U ∩ {z | IsMaxOn (norm ∘ f) U z}
  have hV : ∀ x ∈ V, ‖f x‖ = ‖f c‖ := fun x hx => le_antisymm (hm hx.1) (hx.2 hcU)
  suffices U ⊆ V from fun x hx => hV x (this hx)
  have hVo : IsOpen V := by
    simpa only [ho.mem_nhds_iff, ofPred_and, ofPred_mem_eq]
      using isOpen_setOfPred_mem_nhds_and_isMaxOn_norm hd
  have hVne : (U ∩ V).Nonempty := ⟨c, hcU, hcU, hm⟩
  set W := U ∩ {z | ‖f z‖ ≠ ‖f c‖}
  have hWo : IsOpen W := hd.continuousOn.norm.isOpen_inter_preimage ho isOpen_ne
  have hdVW : Disjoint V W := disjoint_left.mpr fun x hxV hxW => hxW.2 (hV x hxV)
  have hUVW : U ⊆ V ∪ W := fun x hx =>
    (eq_or_ne ‖f x‖ ‖f c‖).imp (fun h => ⟨hx, fun y hy => (hm hy).out.trans_eq h.symm⟩)
      (And.intro hx)
  exact hc.subset_left_of_subset_union hVo hWo hdVW hUVW hVne

Goal state after:
Module: Mathlib.Analysis.Complex.AbelLimit

Goal state before:
pp: f : ℕ → ℂ
l : ℂ
h : Tendsto (fun n ↦ ∑ i ∈ range n, f i) atTop (𝓝 l)
M : ℝ
hM : 1 < M
s : ℕ → ℂ := fun n ↦ ∑ i ∈ range n, f i
g : ℂ → ℂ := fun z ↦ ∑' (n : ℕ), f n * z ^ n
ε : ℝ
εpos : ε > 0
B₁ : ℕ
hB₁ : ∀ n ≥ B₁, ‖∑ i ∈ range n, f i - l‖ < ε / 4 / M
F : ℝ := ∑ i ∈ range B₁, ‖l - s (i + 1)‖
z : ℂ
zn : ‖z‖ < 1
zm : ‖1 - z‖ < M * (1 - ‖z‖)
zd : ‖z - 1‖ < ε / 4 / (F + 1)
B₂ : ℕ
hB₂ : ‖l - ∑' (n : ℕ), f n * z ^ n - (1 - z) * ∑ i ∈ range (max B₁ B₂), (l - ∑ j ∈ range (i + 1), f j) * z ^ i‖ < ε / 2
S₁ : ‖1 - z‖ * ∑ i ∈ range B₁, ‖l - s (i + 1)‖ * ‖z‖ ^ i < ε / 4
⊢ ‖1 - z‖ * (ε / 4 / M) / (1 - ‖z‖) < M * (1 - ‖z‖) * (ε / 4 / M) / (1 - ‖z‖)

Tactic:
gcongr

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.Trigonometric.Complex

Goal state before:
pp: case neg
x : ℂ
h : ¬cos (x / 2) = 0
⊢ 2 * sin (x / 2) * cos (x / 2) = 2 * tan (x / 2) / (1 + tan (x / 2) ^ 2)

Tactic:
· rw [div_eq_mul_inv (2 * tan (x / 2)) (1 + tan (x / 2) ^ 2), inv_one_add_tan_sq h,
      ← tan_mul_cos h]
    ring

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.Trigonometric.Bounds

Goal state before:
pp: case inr
x : ℝ
h : 0 < x
h' : x ≤ 1
hx : |x| = x
this : sin x ≤ x - x ^ 3 / 6 + x ^ 5 / 100
⊢ 0 < x ^ 3 / 6 - x ^ 5 / 100

Tactic:
sub_pos,

Goal state after:
case inr
x : ℝ
h : 0 < x
h' : x ≤ 1
hx : |x| = x
this : sin x ≤ x - x ^ 3 / 6 + x ^ 5 / 100
⊢ x ^ 5 / 100 < x ^ 3 / 6
Module: Mathlib.Analysis.Complex.Angle

Goal state before:
pp: x y : ℂ
hy : ‖1‖ = 1
θ : ℝ
hθ : θ ∈ Ioc (-π) π
⊢ 2 * (1 - (1 - 2 / π ^ 2 * θ ^ 2)) ≤ 2 * (1 - Real.cos θ)

Tactic:
gcongr

Goal state after:
case h
x y : ℂ
hy : ‖1‖ = 1
θ : ℝ
hθ : θ ∈ Ioc (-π) π
⊢ Real.cos θ ≤ 1 - 2 / π ^ 2 * θ ^ 2
Module: Mathlib.Analysis.Complex.Angle

Goal state before:
pp: x y : ℂ
hy : ‖1‖ = 1
θ : ℝ
hθ : θ ∈ Ioc (-π) π
⊢ 2 * (1 - Real.cos θ) ≤ 2 * (1 - (1 - θ ^ 2 / 2))

Tactic:
gcongr

Goal state after:
case h
x y : ℂ
hy : ‖1‖ = 1
θ : ℝ
hθ : θ ∈ Ioc (-π) π
⊢ 1 - θ ^ 2 / 2 ≤ Real.cos θ
Module: Mathlib.Analysis.Complex.BorelCaratheodory

Goal state before:
pp: M : ℝ
w : ℂ
hM : 0 < M
hw : ‖w‖ < 1
⊢ 2 * M * ‖w‖ / ‖1 + w‖ ≤ 2 * M * ‖w‖ / (1 - ‖w‖)

Tactic:
gcongr

Goal state after:
case hdb
M : ℝ
w : ℂ
hM : 0 < M
hw : ‖w‖ < 1
⊢ 1 - ‖w‖ ≤ ‖1 + w‖