mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.SpecialFunctions.Integrability.Basic

Goal state before:
pp: case hst
a b : ℝ
r : ℂ
h : -1 < r.re
c : ℝ
hc : 0 ≤ c
x : ℝ
⊢ x ∈ Ι 0 c → (fun x ↦ x ^ r.re) x = (fun t ↦ ‖↑t ^ r‖) x

Tactic:
hx

Goal state after:
case hst
a b : ℝ
r : ℂ
h : -1 < r.re
c : ℝ
hc : 0 ≤ c
x : ℝ
hx : x ∈ Ι 0 c
⊢ (fun x ↦ x ^ r.re) x = (fun t ↦ ‖↑t ^ r‖) x
Module: Mathlib.Analysis.Complex.Poisson

Goal state before:
pp: E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
f : ℂ → E
R : ℝ
w : ℂ
inst✝ : CompleteSpace E
hf : DiffContOnCl ℂ f (ball 0 R)
hw : w ∈ ball 0 R
hR : 0 < R
h₁w : w ≠ 0
W : ℂ := ↑R * cexp (↑w.arg * I)
q : ℝ := ‖w‖ / R
h₁q : 0 < q
h₂q : q < 1
η₀ : ∀ {x : ℂ}, ‖x‖ ≤ R → ↑q * x - W ≠ 0
h0 : ∮ (z : ℂ) in C(0, R), z⁻¹ • (↑q * z / (↑q * z - W)) • f z = 0
⊢ Real.circleAverage (fun z ↦ (z / (z - w) - q • z / (q • z - W)) • f z) 0 R =
    Real.circleAverage (fun z ↦ (z / (z - w)) • f z) 0 R - Real.circleAverage (fun z ↦ (q • z / (q • z - W)) • f z) 0 R

Tactic:
simp_rw [sub_smul]
      have h₁ : ∀ z ∈ sphere 0 R, z - w ≠ 0 := by aesop (add simp sub_eq_zero)
      have h₃ : ContinuousOn f (sphere 0 R) :=
        hf.2.mono <| sphere_subset_closedBall.trans_eq (closure_ball 0 hR.ne').symm
      rw [circleAverage_fun_sub]
      all_goals
        apply ContinuousOn.circleIntegrable hR.le
        fun_prop (disch := aesop)

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

Goal state before:
pp: E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℂ E
f : ℂ → E
R : ℝ
w : ℂ
inst✝ : CompleteSpace E
c : ℂ
hf : DiffContOnCl ℂ f (ball c R)
hw : w ∈ ball c R
hR : 0 < R
⊢ MapsTo (fun z ↦ z + c) (ball 0 R) (ball c R)

Tactic:
intro; aesop

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

Goal state before:
pp: case refine_2
R : ℝ
w c : ℂ
hw : w ∈ ball c R
this : Disjoint {w} (ball c R)ᶜ
d : ℝ
hd : 0 < d
h_disj : Disjoint (ball w d) (thickening d (ball c R)ᶜ)
x : ℂ
⊢ x ∈ ball w d → ∀ (θ : ℝ), d ≤ ‖circleMap c R θ - x‖

Tactic:
hx

Goal state after:
case refine_2
R : ℝ
w c : ℂ
hw : w ∈ ball c R
this : Disjoint {w} (ball c R)ᶜ
d : ℝ
hd : 0 < d
h_disj : Disjoint (ball w d) (thickening d (ball c R)ᶜ)
x : ℂ
hx : x ∈ ball w d
⊢ ∀ (θ : ℝ), d ≤ ‖circleMap c R θ - x‖
Module: Mathlib.Analysis.SpecialFunctions.Integrability.Basic

Goal state before:
pp: a b x : ℝ
⊢ 0 < x → IntervalIntegrable log volume 0 x

Tactic:
hx

Goal state after:
a b x : ℝ
hx : 0 < x
⊢ IntervalIntegrable log volume 0 x
Module: Mathlib.Analysis.SpecialFunctions.Integrability.Basic

Goal state before:
pp: a b x : ℝ
hx : 0 < x
⊢ IntervalIntegrable log volume 0 x

Tactic:
apply IntervalIntegrable.trans (b := 1)

Goal state after:
case hab
a b x : ℝ
hx : 0 < x
⊢ IntervalIntegrable log volume 0 1

case hbc
a b x : ℝ
hx : 0 < x
⊢ IntervalIntegrable log volume 1 x
Module: Mathlib.Analysis.SpecialFunctions.Log.PosLog

Goal state before:
pp: x : ℝ
⊢ x ∈ Set.Ici 0 → ∀ ⦃b : ℝ⦄, b ∈ Set.Ici 0 → x ≤ b → log⁺ x ≤ log⁺ b

Tactic:
hx

Goal state after:
x : ℝ
hx : x ∈ Set.Ici 0
⊢ ∀ ⦃b : ℝ⦄, b ∈ Set.Ici 0 → x ≤ b → log⁺ x ≤ log⁺ b
Module: Mathlib.Analysis.Complex.Poisson

Goal state before:
pp: E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
f : ℂ → E
R : ℝ
w : ℂ
hg : CircleIntegrable f 0 R
hw : w ∈ ball 0 R
hR : 0 < R
d : ℝ
hd : d > 0
hsub : ball w d ⊆ ball 0 R
hdist : ∀ x ∈ ball w d, ∀ (θ : ℝ), d ≤ ‖circleMap 0 R θ - x‖
hgm : AEStronglyMeasurable (fun θ ↦ f (circleMap 0 R θ)) (volume.restrict (uIoc 0 (2 * π)))
θ : ℝ
a✝ : θ ∈ uIoc 0 (2 * π)
x : ℂ
⊢ x ∈ ball w d →
    ‖(2 * circleMap 0 R θ / (circleMap 0 R θ - x) ^ 2) • f (circleMap 0 R θ)‖ ≤
      2 * R * (d ^ 2)⁻¹ * ‖f (circleMap 0 R θ)‖

Tactic:
hx

Goal state after:
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
f : ℂ → E
R : ℝ
w : ℂ
hg : CircleIntegrable f 0 R
hw : w ∈ ball 0 R
hR : 0 < R
d : ℝ
hd : d > 0
hsub : ball w d ⊆ ball 0 R
hdist : ∀ x ∈ ball w d, ∀ (θ : ℝ), d ≤ ‖circleMap 0 R θ - x‖
hgm : AEStronglyMeasurable (fun θ ↦ f (circleMap 0 R θ)) (volume.restrict (uIoc 0 (2 * π)))
θ : ℝ
a✝ : θ ∈ uIoc 0 (2 * π)
x : ℂ
hx : x ∈ ball w d
⊢ ‖(2 * circleMap 0 R θ / (circleMap 0 R θ - x) ^ 2) • f (circleMap 0 R θ)‖ ≤ 2 * R * (d ^ 2)⁻¹ * ‖f (circleMap 0 R θ)‖
Module: Mathlib.Analysis.Complex.Poisson

Goal state before:
pp: E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
f : ℂ → E
R : ℝ
w : ℂ
hg : CircleIntegrable f 0 R
hw : w ∈ ball 0 R
hR : 0 < R
d : ℝ
hd : d > 0
hsub : ball w d ⊆ ball 0 R
hdist : ∀ x ∈ ball w d, ∀ (θ : ℝ), d ≤ ‖circleMap 0 R θ - x‖
hgm : AEStronglyMeasurable (fun θ ↦ f (circleMap 0 R θ)) (volume.restrict (uIoc 0 (2 * π)))
θ : ℝ
a✝ : θ ∈ uIoc 0 (2 * π)
x : ℂ
⊢ x ∈ ball w d →
    HasDerivAt (fun x ↦ herglotzRieszKernel 0 x (circleMap 0 R θ) • f (circleMap 0 R θ))
      ((2 * circleMap 0 R θ / (circleMap 0 R θ - x) ^ 2) • f (circleMap 0 R θ)) x

Tactic:
hx

Goal state after:
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
f : ℂ → E
R : ℝ
w : ℂ
hg : CircleIntegrable f 0 R
hw : w ∈ ball 0 R
hR : 0 < R
d : ℝ
hd : d > 0
hsub : ball w d ⊆ ball 0 R
hdist : ∀ x ∈ ball w d, ∀ (θ : ℝ), d ≤ ‖circleMap 0 R θ - x‖
hgm : AEStronglyMeasurable (fun θ ↦ f (circleMap 0 R θ)) (volume.restrict (uIoc 0 (2 * π)))
θ : ℝ
a✝ : θ ∈ uIoc 0 (2 * π)
x : ℂ
hx : x ∈ ball w d
⊢ HasDerivAt (fun x ↦ herglotzRieszKernel 0 x (circleMap 0 R θ) • f (circleMap 0 R θ))
    ((2 * circleMap 0 R θ / (circleMap 0 R θ - x) ^ 2) • f (circleMap 0 R θ)) x
Module: Mathlib.Analysis.SpecialFunctions.Integrals.PosLogEqCircleAverage

Goal state before:
pp: a : ℂ
h : ‖a‖ < 1
x : ℂ
⊢ x ∈ closedBall 0 |1| → InnerProductSpace.HarmonicAt (fun x ↦ log ‖1 - x * a‖) x

Tactic:
hx

Goal state after:
a : ℂ
h : ‖a‖ < 1
x : ℂ
hx : x ∈ closedBall 0 |1|
⊢ InnerProductSpace.HarmonicAt (fun x ↦ log ‖1 - x * a‖) x
Module: Mathlib.Analysis.SpecialFunctions.Integrability.LogMeromorphic

Goal state before:
pp: case hg.hf
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
c : ℂ
R : ℝ
f : ℂ → E
hf : MeromorphicOn f (sphere c |R|)
t₀ : ∀ (u : ↑(sphere c |R|)), meromorphicOrderAt f ↑u ≠ ⊤
g : ℂ → E
h₁g : AnalyticOnNhd ℂ g (sphere c |R|)
h₂g : ∀ (u : ↑(sphere c |R|)), g ↑u ≠ 0
h₃g : f =ᶠ[codiscreteWithin (sphere c |R|)] (∏ᶠ (u : ℂ), (fun x ↦ x - u) ^ (divisor f (sphere c |R|)) u) • g
h₄g :
  (fun x ↦ log ‖f x‖) =ᶠ[codiscreteWithin (sphere c |R|)]
    (∑ᶠ (u : ℂ), fun x ↦ ↑((divisor f (sphere c |R|)) u) * log ‖x - u‖) + fun x ↦ log ‖g x‖
x : ℝ
⊢ x ∈ [[0, 2 * π]] → circleMap c R x ∈ sphere c |R|

Tactic:
hx

Goal state after:
case hg.hf
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
c : ℂ
R : ℝ
f : ℂ → E
hf : MeromorphicOn f (sphere c |R|)
t₀ : ∀ (u : ↑(sphere c |R|)), meromorphicOrderAt f ↑u ≠ ⊤
g : ℂ → E
h₁g : AnalyticOnNhd ℂ g (sphere c |R|)
h₂g : ∀ (u : ↑(sphere c |R|)), g ↑u ≠ 0
h₃g : f =ᶠ[codiscreteWithin (sphere c |R|)] (∏ᶠ (u : ℂ), (fun x ↦ x - u) ^ (divisor f (sphere c |R|)) u) • g
h₄g :
  (fun x ↦ log ‖f x‖) =ᶠ[codiscreteWithin (sphere c |R|)]
    (∑ᶠ (u : ℂ), fun x ↦ ↑((divisor f (sphere c |R|)) u) * log ‖x - u‖) + fun x ↦ log ‖g x‖
x : ℝ
hx : x ∈ [[0, 2 * π]]
⊢ circleMap c R x ∈ sphere c |R|
Module: Mathlib.Analysis.SpecialFunctions.Integrals.PosLogEqCircleAverage

Goal state before:
pp: a : ℂ
h : ‖a‖ = 1
ζ : ℝ
hζ : a⁻¹ = circleMap 0 1 ζ
x : ℝ
⊢ x ∈ [[0, 2 * π]] → (fun x ↦ log ‖circleMap 0 1 x - 1‖) x = (fun x ↦ log (4 * sin (x / 2) ^ 2) / 2) x

Tactic:
hx

Goal state after:
a : ℂ
h : ‖a‖ = 1
ζ : ℝ
hζ : a⁻¹ = circleMap 0 1 ζ
x : ℝ
hx : x ∈ [[0, 2 * π]]
⊢ (fun x ↦ log ‖circleMap 0 1 x - 1‖) x = (fun x ↦ log (4 * sin (x / 2) ^ 2) / 2) x
Module: Mathlib.Analysis.SpecialFunctions.Integrability.LogMeromorphic

Goal state before:
pp: case h₀
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
c : ℂ
R : ℝ
f : ℂ → E
hf : MeromorphicOn f (sphere c |R|)
t₀ : ∀ (u : ↑(sphere c |R|)), meromorphicOrderAt f ↑u ≠ ⊤
g : ℂ → E
h₁g : AnalyticOnNhd ℂ g (sphere c |R|)
h₂g : ∀ (u : ↑(sphere c |R|)), g ↑u ≠ 0
h₃g : f =ᶠ[codiscreteWithin (sphere c |R|)] (∏ᶠ (u : ℂ), (fun x ↦ x - u) ^ (divisor f (sphere c |R|)) u) • g
h₄g :
  (fun x ↦ log ‖f x‖) =ᶠ[codiscreteWithin (sphere c |R|)]
    (∑ᶠ (u : ℂ), fun x ↦ ↑((divisor f (sphere c |R|)) u) * log ‖x - u‖) + fun x ↦ log ‖g x‖
x : ℝ
⊢ x ∈ [[0, 2 * π]] → ‖g (circleMap c R x)‖ ≠ 0

Tactic:
hx

Goal state after:
case h₀
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
c : ℂ
R : ℝ
f : ℂ → E
hf : MeromorphicOn f (sphere c |R|)
t₀ : ∀ (u : ↑(sphere c |R|)), meromorphicOrderAt f ↑u ≠ ⊤
g : ℂ → E
h₁g : AnalyticOnNhd ℂ g (sphere c |R|)
h₂g : ∀ (u : ↑(sphere c |R|)), g ↑u ≠ 0
h₃g : f =ᶠ[codiscreteWithin (sphere c |R|)] (∏ᶠ (u : ℂ), (fun x ↦ x - u) ^ (divisor f (sphere c |R|)) u) • g
h₄g :
  (fun x ↦ log ‖f x‖) =ᶠ[codiscreteWithin (sphere c |R|)]
    (∑ᶠ (u : ℂ), fun x ↦ ↑((divisor f (sphere c |R|)) u) * log ‖x - u‖) + fun x ↦ log ‖g x‖
x : ℝ
hx : x ∈ [[0, 2 * π]]
⊢ ‖g (circleMap c R x)‖ ≠ 0
Module: Mathlib.Analysis.SpecialFunctions.Integrals.PosLogEqCircleAverage

Goal state before:
pp: a : ℂ
h : 1 < ‖a‖
x : ℂ
⊢ x ∈ closedBall 0 |1| → InnerProductSpace.HarmonicAt (fun x ↦ log ‖x - a‖) x

Tactic:
hx

Goal state after:
a : ℂ
h : 1 < ‖a‖
x : ℂ
hx : x ∈ closedBall 0 |1|
⊢ InnerProductSpace.HarmonicAt (fun x ↦ log ‖x - a‖) x
Module: Mathlib.Analysis.Complex.PhragmenLindelof

Goal state before:
pp: case refine_3
E : Type u_1
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℂ E
f : ℂ → E
hd : DiffContOnCl ℂ f {z | 0 < z.re}
hexp : ∃ c < 2, ∃ B, f =O[cobounded ℂ ⊓ 𝓟 {z | 0 < z.re}] fun z ↦ expR (B * ‖z‖ ^ c)
hre : SuperpolynomialDecay atTop expR fun x ↦ ‖f ↑x‖
C : ℝ
hC : ∀ (x : ℝ), ‖f (↑x * I)‖ ≤ C
g : ℕ → ℂ → E := fun n z ↦ cexp z ^ n • f z
hg : ∀ (n : ℕ) (z : ℂ), ‖g n z‖ = expR z.re ^ n * ‖f z‖
z : ℂ
hz : 0 < z.re
n : ℕ
y : ℝ
⊢ ‖f (↑y * I)‖ ≤ C

Tactic:
exact hC y

Goal state after:
Module: Mathlib.Analysis.Complex.Polynomial.GaussLucas

Goal state before:
pp: case neg
P : ℂ[X]
hP : 0 < P.degree
z : ℂ
hP₀ : P ≠ 0
hPz : ¬eval z P = 0
⊢ 0 < ∑ w ∈ P.roots.toFinset, ↑(rootMultiplicity w P) / ‖z - w‖ ^ 2

Tactic:
apply Finset.sum_pos

Goal state after:
case neg.h
P : ℂ[X]
hP : 0 < P.degree
z : ℂ
hP₀ : P ≠ 0
hPz : ¬eval z P = 0
⊢ ∀ i ∈ P.roots.toFinset, 0 < ↑(rootMultiplicity i P) / ‖z - i‖ ^ 2

case neg.hs
P : ℂ[X]
hP : 0 < P.degree
z : ℂ
hP₀ : P ≠ 0
hPz : ¬eval z P = 0
⊢ P.roots.toFinset.Nonempty
Module: Mathlib.Analysis.SpecialFunctions.Integrals.Basic

Goal state before:
pp: a b : ℝ
n : ℕ
C : ℝ := cos b ^ (n + 1) * sin b - cos a ^ (n + 1) * sin a
h : ∀ (α β γ : ℝ), β * α * γ * α = β * (α * α * γ)
hu : ∀ x ∈ [[a, b]], HasDerivAt (fun y ↦ cos y ^ (n + 1)) (-↑(n + 1) * sin x * cos x ^ n) x
hv : ∀ x ∈ [[a, b]], HasDerivAt sin (cos x) x
H :
  ∫ (x : ℝ) in a..b, cos x ^ (n + 1) * cos x =
    cos b ^ (n + 1) * sin b - cos a ^ (n + 1) * sin a - ∫ (x : ℝ) in a..b, -↑(n + 1) * sin x * cos x ^ n * sin x
⊢ ∫ (x : ℝ) in a..b, cos x ^ (n + 1) * cos x = C + (↑n + 1) * ∫ (x : ℝ) in a..b, sin x ^ 2 * cos x ^ n

Tactic:
simp [C, H, h, sq, -neg_add_rev]

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.Integrals.Basic

Goal state before:
pp: a b : ℝ
n : ℕ
⊢ ∫ (x : ℝ) in a..b, cos x ^ (n + 2) =
    (cos b ^ (n + 1) * sin b - cos a ^ (n + 1) * sin a + (↑n + 1) * ∫ (x : ℝ) in a..b, cos x ^ n) -
      (↑n + 1) * ∫ (x : ℝ) in a..b, cos x ^ (n + 2)

Tactic:
by
  let C := cos b ^ (n + 1) * sin b - cos a ^ (n + 1) * sin a
  have h : ∀ α β γ : ℝ, β * α * γ * α = β * (α * α * γ) := fun α β γ => by ring
  have hu : ∀ x ∈ [[a, b]],
      HasDerivAt (fun y => cos y ^ (n + 1)) (-(n + 1 : ℕ) * sin x * cos x ^ n) x :=
    fun x _ => by
      simpa only [mul_right_comm, neg_mul, mul_neg] using! (hasDerivAt_cos x).pow (n + 1)
  have hv : ∀ x ∈ [[a, b]], HasDerivAt sin (cos x) x := fun x _ => hasDerivAt_sin x
  have H := integral_mul_deriv_eq_deriv_mul hu hv ?_ ?_
  · calc
      (∫ x in a..b, cos x ^ (n + 2)) = ∫ x in a..b, cos x ^ (n + 1) * cos x := by
        simp only [_root_.pow_succ]
      _ = C + (n + 1) * ∫ x in a..b, sin x ^ 2 * cos x ^ n := by simp [C, H, h, sq, -neg_add_rev]
      _ = C + (n + 1) * ∫ x in a..b, cos x ^ n - cos x ^ (n + 2) := by
        simp [sin_sq, sub_mul, ← pow_add, add_comm]
      _ = (C + (n + 1) * ∫ x in a..b, cos x ^ n) - (n + 1) * ∫ x in a..b, cos x ^ (n + 2) := by
        rw [integral_sub, mul_sub, add_sub_assoc] <;>
          apply Continuous.intervalIntegrable <;> fun_prop
  all_goals apply Continuous.intervalIntegrable; fun_prop

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

Goal state before:
pp: case succ
f : ℂ → ℂ
c : ℂ
hf : Differentiable ℂ f
z : ℂ
hz : c ≤ z
n : ℕ
h : 0 ≤ iteratedDeriv n (_root_.deriv f) c
⊢ 0 ≤ iteratedDeriv n (_root_.deriv fun x ↦ f x - f c) c

Tactic:
funext fun x ↦ deriv_sub_const (f := f) (x := x) (f c)

Goal state after:
case succ
f : ℂ → ℂ
c : ℂ
hf : Differentiable ℂ f
z : ℂ
hz : c ≤ z
n : ℕ
h : 0 ≤ iteratedDeriv n (_root_.deriv f) c
⊢ 0 ≤ iteratedDeriv n (_root_.deriv f) c
Module: Mathlib.Analysis.Complex.RiemannMapping

Goal state before:
pp: U : Set ℂ
hUo : IsOpen U
hUc : IsSimplyConnected U
hU : U ≠ univ
⊢ ∃ f, MapsTo f U (ball 0 1) ∧ InjOn f U ∧ ∀ z ∈ U, deriv f z ≠ 0

Tactic:
rcases exists_injective_not_dense_image_deriv_ne_zero hUo hUc hU with ⟨f, hf_inj, hfd, hdf⟩

Goal state after:
U : Set ℂ
hUo : IsOpen U
hUc : IsSimplyConnected U
hU : U ≠ univ
f : ℂ → ℂ
hf_inj : Injective f
hfd : ¬Dense (f '' U)
hdf : ∀ z ∈ U, deriv f z ≠ 0
⊢ ∃ f, MapsTo f U (ball 0 1) ∧ InjOn f U ∧ ∀ z ∈ U, deriv f z ≠ 0
Module: Mathlib.Order.Monotone.Union

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : StrictMonoOn f s
h₂ : StrictMonoOn f t
hs : IsGreatest s c
ht : IsLeast t c
x : α
⊢ x ∈ s ∪ t → x ≤ c → x ∈ s

Tactic:
hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : StrictMonoOn f s
h₂ : StrictMonoOn f t
hs : IsGreatest s c
ht : IsLeast t c
x : α
hx : x ∈ s ∪ t
⊢ x ≤ c → x ∈ s
Module: Mathlib.Order.Monotone.Union

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : StrictMonoOn f s
h₂ : StrictMonoOn f t
hs : IsGreatest s c
ht : IsLeast t c
A : ∀ x ∈ s ∪ t, x ≤ c → x ∈ s
x : α
⊢ x ∈ s ∪ t → c ≤ x → x ∈ t

Tactic:
hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : StrictMonoOn f s
h₂ : StrictMonoOn f t
hs : IsGreatest s c
ht : IsLeast t c
A : ∀ x ∈ s ∪ t, x ≤ c → x ∈ s
x : α
hx : x ∈ s ∪ t
⊢ c ≤ x → x ∈ t
Module: Mathlib.Order.Monotone.Union

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : StrictMonoOn f s
h₂ : StrictMonoOn f t
hs : IsGreatest s c
ht : IsLeast t c
A : ∀ x ∈ s ∪ t, x ≤ c → x ∈ s
B : ∀ x ∈ s ∪ t, c ≤ x → x ∈ t
x : α
⊢ x ∈ s ∪ t → ∀ ⦃b : α⦄, b ∈ s ∪ t → x < b → f x < f b

Tactic:
hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : StrictMonoOn f s
h₂ : StrictMonoOn f t
hs : IsGreatest s c
ht : IsLeast t c
A : ∀ x ∈ s ∪ t, x ≤ c → x ∈ s
B : ∀ x ∈ s ∪ t, c ≤ x → x ∈ t
x : α
hx : x ∈ s ∪ t
⊢ ∀ ⦃b : α⦄, b ∈ s ∪ t → x < b → f x < f b
Module: Mathlib.Order.Monotone.Union

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : MonotoneOn f s
h₂ : MonotoneOn f t
hs : IsGreatest s c
ht : IsLeast t c
x : α
⊢ x ∈ s ∪ t → x ≤ c → x ∈ s

Tactic:
hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : MonotoneOn f s
h₂ : MonotoneOn f t
hs : IsGreatest s c
ht : IsLeast t c
x : α
hx : x ∈ s ∪ t
⊢ x ≤ c → x ∈ s
Module: Mathlib.Order.Monotone.Union

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : MonotoneOn f s
h₂ : MonotoneOn f t
hs : IsGreatest s c
ht : IsLeast t c
A : ∀ x ∈ s ∪ t, x ≤ c → x ∈ s
x : α
⊢ x ∈ s ∪ t → c ≤ x → x ∈ t

Tactic:
hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : MonotoneOn f s
h₂ : MonotoneOn f t
hs : IsGreatest s c
ht : IsLeast t c
A : ∀ x ∈ s ∪ t, x ≤ c → x ∈ s
x : α
hx : x ∈ s ∪ t
⊢ c ≤ x → x ∈ t
Module: Mathlib.Order.Monotone.Union

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : MonotoneOn f s
h₂ : MonotoneOn f t
hs : IsGreatest s c
ht : IsLeast t c
A : ∀ x ∈ s ∪ t, x ≤ c → x ∈ s
B : ∀ x ∈ s ∪ t, c ≤ x → x ∈ t
x : α
⊢ x ∈ s ∪ t → ∀ ⦃b : α⦄, b ∈ s ∪ t → x ≤ b → f x ≤ f b

Tactic:
hx

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : LinearOrder α
inst✝ : Preorder β
f : α → β
s t : Set α
c : α
h₁ : MonotoneOn f s
h₂ : MonotoneOn f t
hs : IsGreatest s c
ht : IsLeast t c
A : ∀ x ∈ s ∪ t, x ≤ c → x ∈ s
B : ∀ x ∈ s ∪ t, c ≤ x → x ∈ t
x : α
hx : x ∈ s ∪ t
⊢ ∀ ⦃b : α⦄, b ∈ s ∪ t → x ≤ b → f x ≤ f b
Module: Mathlib.Analysis.Complex.Tietze

Goal state before:
pp: 𝕜 : Type v
inst✝³ : RCLike 𝕜
E : Type w
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : FiniteDimensional 𝕜 E
⊢ TietzeExtension ↑(Metric.closedBall 0 1)

Tactic:
have : NormedSpace ℝ E := NormedSpace.restrictScalars ℝ 𝕜 E
  have : IsScalarTower ℝ 𝕜 E := Real.isScalarTower
  -- I didn't find this retract in Mathlib.
  let g : E → E := fun x ↦ ‖x‖⁻¹ • x
  classical
  suffices this : Continuous (piecewise (Metric.closedBall 0 1) id g) by
    refine .of_retract ⟨Subtype.val, by fun_prop⟩ ⟨_, this.codRestrict fun x ↦ ?_⟩ ?_
    · by_cases hx : x ∈ Metric.closedBall 0 1
      · simpa [piecewise_eq_of_mem (hi := hx)] using hx
      · simp only [g, piecewise_eq_of_notMem (hi := hx), RCLike.real_smul_eq_coe_smul (K := 𝕜)]
        by_cases hx' : x = 0 <;> simp [hx']
    · ext x
      simp
  refine continuous_piecewise (fun x hx ↦ ?_) continuousOn_id ?_
  · replace hx : ‖x‖ = 1 := by simpa [frontier_closedBall (0 : E) one_ne_zero] using hx
    simp [g, hx]
  · refine continuousOn_id.norm.inv₀ ?_ |>.smul continuousOn_id
    simp only [closure_compl, interior_closedBall (0 : E) one_ne_zero, mem_compl_iff,
      Metric.mem_ball, dist_zero_right, not_lt, id_eq, ne_eq, norm_eq_zero]
    exact fun x hx ↦ norm_pos_iff.mp <| one_pos.trans_le hx

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

Goal state before:
pp: case neg
X : Type u
inst✝⁵ : TopologicalSpace X
inst✝⁴ : NormalSpace X
s : Set X
hs : IsClosed s
𝕜 : Type v
inst✝³ : RCLike 𝕜
E : Type w
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : FiniteDimensional 𝕜 E
f : ↑s →ᵇ E
hf : ¬‖f‖ = 0
this : TietzeExtension ↑(Metric.closedBall 0 ‖f‖)
hf' : ∀ (x : ↑s), f x ∈ Metric.closedBall 0 ‖f‖
g : C(X, E)
hg : ContinuousMap.restrict s g = ↑f
hg_mem : ∀ (x : X), ‖g x‖ ≤ ‖f‖
g' : X →ᵇ E := ofNormedAddCommGroup ⇑g ⋯ ‖f‖ hg_mem
x : ↑s
hx : f x = g' ↑x
⊢ ‖f x‖ ≤ ‖g'‖

Tactic:
hx

Goal state after:
case neg
X : Type u
inst✝⁵ : TopologicalSpace X
inst✝⁴ : NormalSpace X
s : Set X
hs : IsClosed s
𝕜 : Type v
inst✝³ : RCLike 𝕜
E : Type w
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : FiniteDimensional 𝕜 E
f : ↑s →ᵇ E
hf : ¬‖f‖ = 0
this : TietzeExtension ↑(Metric.closedBall 0 ‖f‖)
hf' : ∀ (x : ↑s), f x ∈ Metric.closedBall 0 ‖f‖
g : C(X, E)
hg : ContinuousMap.restrict s g = ↑f
hg_mem : ∀ (x : X), ‖g x‖ ≤ ‖f‖
g' : X →ᵇ E := ofNormedAddCommGroup ⇑g ⋯ ‖f‖ hg_mem
x : ↑s
hx : f x = g' ↑x
⊢ ‖g' ↑x‖ ≤ ‖g'‖
Module: Mathlib.LinearAlgebra.Matrix.Charpoly.Disc

Goal state before:
pp: R : Type u_1
n : Type u_2
inst✝² : CommRing R
inst✝¹ : Fintype n
inst✝ : DecidableEq n
A : Matrix n n R
hn : Fintype.card n = 2
a✝ : Nontrivial R
⊢ A.charpoly.coeff 1 ^ 2 - 4 * A.charpoly.coeff 0 * A.charpoly.coeff 2 = A.trace ^ 2 - 4 * A.det

Tactic:
simp [A.charpoly_of_card_eq_two hn]

Goal state after:
Module: Mathlib.Topology.TietzeExtension

Goal state before:
pp: X : Type u_1
Y : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
inst✝ : NormalSpace Y
f : X →ᵇ ℝ
e : C(X, Y)
he : IsClosedEmbedding ⇑e
F : (X →ᵇ ℝ) → Y →ᵇ ℝ
hF_norm : ∀ (f : X →ᵇ ℝ), ‖F f‖ ≤ ‖f‖ / 3
hF_dist : ∀ (f : X →ᵇ ℝ), dist ((F f).compContinuous e) f ≤ 2 / 3 * ‖f‖
⊢ ∃ g, ‖g‖ = ‖f‖ ∧ g.compContinuous e = f

Tactic:
set g : ℕ → Y →ᵇ ℝ := fun n => (fun g => g + F (f - g.compContinuous e))^[n] 0

Goal state after:
X : Type u_1
Y : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
inst✝ : NormalSpace Y
f : X →ᵇ ℝ
e : C(X, Y)
he : IsClosedEmbedding ⇑e
F : (X →ᵇ ℝ) → Y →ᵇ ℝ
hF_norm : ∀ (f : X →ᵇ ℝ), ‖F f‖ ≤ ‖f‖ / 3
hF_dist : ∀ (f : X →ᵇ ℝ), dist ((F f).compContinuous e) f ≤ 2 / 3 * ‖f‖
g : ℕ → Y →ᵇ ℝ := fun n ↦ (fun g ↦ g + F (f - g.compContinuous e))^[n] 0
⊢ ∃ g, ‖g‖ = ‖f‖ ∧ g.compContinuous e = f
Module: Mathlib.Analysis.Complex.UpperHalfPlane.Topology

Goal state before:
pp: z : ℂ
hz : 0 < z.im
x : ℂ
⊢ 0 < x.im → (UpperHalfPlane.coe ∘ ↑ofComplex) x = id x

Tactic:
hx

Goal state after:
z : ℂ
hz : 0 < z.im
x : ℂ
hx : 0 < x.im
⊢ (UpperHalfPlane.coe ∘ ↑ofComplex) x = id x
Module: Mathlib.Analysis.Complex.UpperHalfPlane.MoebiusAction

Goal state before:
pp: z : ℍ
⊢ ModularGroup.S • z = { coe := (-↑z)⁻¹, coe_im_pos := ⋯ }

Tactic:
specialLinearGroup_apply

Goal state after:
z : ℍ
⊢ {
      coe :=
        (↑((algebraMap ℤ ℝ) (↑ModularGroup.S 0 0)) * ↑z + ↑((algebraMap ℤ ℝ) (↑ModularGroup.S 0 1))) /
          (↑((algebraMap ℤ ℝ) (↑ModularGroup.S 1 0)) * ↑z + ↑((algebraMap ℤ ℝ) (↑ModularGroup.S 1 1))),
      coe_im_pos := ⋯ } =
    { coe := (-↑z)⁻¹, coe_im_pos := ⋯ }
Module: Mathlib.RingTheory.Norm.Transitivity

Goal state before:
pp: R : Type u_1
S : Type u_2
n : Type u_4
m : Type u_5
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
M : Matrix m m S
inst✝³ : DecidableEq m
inst✝² : DecidableEq n
k : m
inst✝¹ : Fintype m
inst✝ : Fintype n
f : S →+* Matrix n n R
⊢ (((compRingEquiv m n R).toRingHom.comp (f.mapMatrix.comp (evalRingHom 0).mapMatrix)) (cornerAddX M k)).det =
    (((↑(compRingEquiv m n R)).comp f.mapMatrix) M).det

Tactic:
RingHom.comp_apply

Goal state after:
R : Type u_1
S : Type u_2
n : Type u_4
m : Type u_5
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
M : Matrix m m S
inst✝³ : DecidableEq m
inst✝² : DecidableEq n
k : m
inst✝¹ : Fintype m
inst✝ : Fintype n
f : S →+* Matrix n n R
⊢ ((compRingEquiv m n R).toRingHom (f.mapMatrix ((evalRingHom 0).mapMatrix (cornerAddX M k)))).det =
    (↑(compRingEquiv m n R) (f.mapMatrix M)).det
Module: Mathlib.RingTheory.Norm.Transitivity

Goal state before:
pp: R : Type u_1
S : Type u_2
n : Type u_4
m : Type u_5
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
M : Matrix m m S
inst✝³ : DecidableEq m
inst✝² : DecidableEq n
inst✝¹ : Fintype m
inst✝ : Fintype n
f : S →+* Matrix n n R
x✝ : ℕ
l : Fintype.card m = x✝
⊢ (f M.det).det = ((comp m m n n R) (M.map ⇑f)).det

Tactic:
induction l : Fintype.card m generalizing R S m with

Goal state after:
Module: Mathlib.Topology.TietzeExtension

Goal state before:
pp: Y : Type u_2
inst✝² : TopologicalSpace Y
inst✝¹ : NormalSpace Y
s : Set Y
f : ↑s →ᵇ ℝ
hs : IsClosed[inst✝²] s
t : Set ℝ
inst✝ : t.OrdConnected
hf : ∀ (x : ↑s), f x ∈ t
hne : t.Nonempty
⊢ ∃ g, (∀ (y : Y), g y ∈ t) ∧ g.domRestrict s = f

Tactic:
by
  obtain ⟨g, hg, hgf⟩ :=
    exists_extension_forall_mem_of_isClosedEmbedding f hf hne hs.isClosedEmbedding_subtypeVal
  exact ⟨g, hg, DFunLike.coe_injective hgf⟩

Goal state after: