mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Geometry.Convex.Cone.DualFinite

Goal state before:
pp: case h
R : Type u_1
M : Type u_2
N : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : PartialOrder R
inst✝⁴ : IsOrderedRing R
inst✝³ : AddCommGroup M
inst✝² : Module R M
inst✝¹ : AddCommGroup N
inst✝ : Module R N
p : M →ₗ[R] N →ₗ[R] R
s : Set M
hs : s.Finite
⊢ dual p ↑hs.toFinset = dual p s

Tactic:
Set.Finite.coe_toFinset

Goal state after:
case h
R : Type u_1
M : Type u_2
N : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : PartialOrder R
inst✝⁴ : IsOrderedRing R
inst✝³ : AddCommGroup M
inst✝² : Module R M
inst✝¹ : AddCommGroup N
inst✝ : Module R N
p : M →ₗ[R] N →ₗ[R] R
s : Set M
hs : s.Finite
⊢ dual p s = dual p s
Module: Mathlib.FieldTheory.RatFunc.Luroth

Goal state before:
pp: K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
h : E ≠ ⊥
⊢ m E ≤ (Bivariate.swap (Φ E)).natDegree

Tactic:
rw [← sum_monomial_eq (Φ E), sum_def, map_sum]

Goal state after:
K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
h : E ≠ ⊥
⊢ m E ≤ (∑ x ∈ (Φ E).support, Bivariate.swap ((monomial x) ((Φ E).coeff x))).natDegree
Module: Mathlib.Geometry.Convex.Cone.Face.Basic

Goal state before:
pp: R : Type u_1
M : Type u_2
inst✝⁵ : Semiring R
inst✝⁴ : PartialOrder R
inst✝³ : IsOrderedRing R
inst✝² : AddCommGroup M
inst✝¹ : Module R M
C F : PointedCone R M
ι : Type u_4
inst✝ : Fintype ι
f : ι → M
hF : F.IsFaceOf C
hsC : ∀ (i : ι), f i ∈ C
hs : ∑ i, f i ∈ F
i : ι
⊢ f i ∈ F

Tactic:
by classical
  apply hF.mem_of_add_mem_left (hsC i) (sum_mem (fun j (_ : j ∈ Finset.univ.erase i) ↦ hsC j))
  simp [hs]

Goal state after:
Module: Mathlib.FieldTheory.RatFunc.Luroth

Goal state before:
pp: K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
h : E ≠ ⊥
⊢ Polynomial.C ((algebraMap K[X] K⟮X⟯) (g E)) *
        Polynomial.map (((algebraMap (↥E) K⟮X⟯).comp ↑(inclusion ⋯)).comp (algebraMap K ↥K⟮generator E⟯))
          (generator E).num -
      Polynomial.C
          ((algebraMap K[X] K⟮X⟯) (g E) *
            ↑⟨(algebraMap K[X] K⟮X⟯) (generator E).num / (algebraMap K[X] K⟮X⟯) (generator E).denom, ⋯⟩) *
        Polynomial.map (((algebraMap (↥E) K⟮X⟯).comp ↑(inclusion ⋯)).comp (algebraMap K ↥K⟮generator E⟯))
          (generator E).denom =
    Polynomial.map (algebraMap K[X] K⟮X⟯) (θ E)

Tactic:
mul_div_cancel₀ _ (algebraMap_ne_zero (generator E).denom_ne_zero),

Goal state after:
K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
h : E ≠ ⊥
⊢ Polynomial.C ((algebraMap K[X] K⟮X⟯) (g E)) *
        Polynomial.map (((algebraMap (↥E) K⟮X⟯).comp ↑(inclusion ⋯)).comp (algebraMap K ↥K⟮generator E⟯))
          (generator E).num -
      Polynomial.C ((algebraMap K[X] K⟮X⟯) (generator E).num) *
        Polynomial.map (((algebraMap (↥E) K⟮X⟯).comp ↑(inclusion ⋯)).comp (algebraMap K ↥K⟮generator E⟯))
          (generator E).denom =
    Polynomial.map (algebraMap K[X] K⟮X⟯) (θ E)
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Rotation

Goal state before:
pp: V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
⊢ o.oangle y ((o.rotation (o.oangle x y)) x) = 0

Tactic:
rw [oangle_rev]

Goal state after:
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
⊢ -o.oangle ((o.rotation (o.oangle x y)) x) y = 0
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
⊢ o.oangle (-x) (- -y) = o.oangle x (- - -y)

Tactic:
oangle_neg_neg,

Goal state after:
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
⊢ o.oangle x (-y) = o.oangle x (- - -y)
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Rotation

Goal state before:
pp: case h
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
f : V ≃ₗᵢ[ℝ] V
hd : 0 < LinearMap.det ↑f.toLinearEquiv
this : Nontrivial V
x : V
hx : x ≠ 0
⊢ f.toLinearEquiv = (o.rotation (o.oangle x (f x))).toLinearEquiv

Tactic:
apply LinearEquiv.toLinearMap_injective

Goal state after:
case h
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
f : V ≃ₗᵢ[ℝ] V
hd : 0 < LinearMap.det ↑f.toLinearEquiv
this : Nontrivial V
x : V
hx : x ≠ 0
⊢ ↑f.toLinearEquiv = ↑(o.rotation (o.oangle x (f x))).toLinearEquiv
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Rotation

Goal state before:
pp: case neg.mpr
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
H : x ≠ 0 ∧ y ≠ 0
⊢ (∃ r, r • (o.rotation ↑(π / 2)) x = y) →
    (∃ r, 0 < r ∧ y = r • (o.rotation ↑(π / 2)) x) ∨ ∃ r, 0 < r ∧ y = -r • (o.rotation ↑(π / 2)) x

Tactic:
rintro ⟨r, rfl⟩
    rcases lt_trichotomy 0 r with (hr0 | rfl | hr0)
    · grind
    · simp_all
    · right
      use -r
      simp_all

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Affine

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
p₁ p₂ p₃ : P
h : ∡ p₁ p₂ p₃ ≠ 0
⊢ p₁ -ᵥ p₂ ≠ 0

Tactic:
exact o.left_ne_zero_of_oangle_ne_zero h

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
hn : x ≠ y
h : ‖x‖ = ‖y‖
⊢ o.oangle y x = ↑π - 2 • o.oangle (y - x) y

Tactic:
rw [two_zsmul]

Goal state after:
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
hn : x ≠ y
h : ‖x‖ = ‖y‖
⊢ o.oangle y x = ↑π - (o.oangle (y - x) y + o.oangle (y - x) y)
Module: Mathlib.Geometry.Euclidean.Angle.Unoriented.RightAngle

Goal state before:
pp: V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ⟪x, y⟫ = 0
⊢ angle x (x + y) ≤ π / 2

Tactic:
rw [angle_add_eq_arccos_of_inner_eq_zero h, Real.arccos_le_pi_div_two]
  exact div_nonneg (norm_nonneg _) (norm_nonneg _)

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: case inl
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
hx : x ≠ 0
hy : y ≠ 0
h0 : 0 ≤ InnerProductGeometry.angle x y
hpi : InnerProductGeometry.angle x y ≤ π
h : o.oangle x y = ↑(InnerProductGeometry.angle x y)
⊢ 0 ≤ InnerProductGeometry.angle x y ∧ InnerProductGeometry.angle x y ≤ π

Tactic:
exact ⟨h0, hpi⟩

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: case inr
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
hx : x ≠ 0
hy : y ≠ 0
h0 : 0 ≤ InnerProductGeometry.angle x y
hpi : InnerProductGeometry.angle x y ≤ π
h : o.oangle x y = -↑(InnerProductGeometry.angle x y)
⊢ 0 ≤ InnerProductGeometry.angle x y ∧ InnerProductGeometry.angle x y ≤ π

Tactic:
exact ⟨h0, hpi⟩

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Unoriented.RightAngle

Goal state before:
pp: case inl
V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ⟪x, y⟫ = 0
h0 : x ≠ 0
⊢ ‖x‖ / (‖x‖ / ‖x + y‖) = ‖x + y‖

pp: case inr
V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ⟪x, y⟫ = 0
h0 : y = 0
⊢ ‖x‖ / (‖x‖ / ‖x + y‖) = ‖x + y‖

Tactic:
· rw [div_div_eq_mul_div, mul_comm, div_eq_mul_inv, mul_inv_cancel_right₀ (norm_ne_zero_iff.2 h0)]

Goal state after:
case inr
V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ⟪x, y⟫ = 0
h0 : y = 0
⊢ ‖x‖ / (‖x‖ / ‖x + y‖) = ‖x + y‖
Module: Mathlib.Geometry.Euclidean.Angle.Unoriented.RightAngle

Goal state before:
pp: case inr
V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ⟪x, y⟫ = 0
h0 : y ≠ 0
⊢ ‖y‖ / (‖y‖ / ‖x‖) = ‖x‖

Tactic:
· rw [div_div_eq_mul_div, mul_comm, div_eq_mul_inv, mul_inv_cancel_right₀ (norm_ne_zero_iff.2 h0)]

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Affine

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
p₁ p₂ p₃ p₄ p₅ p₆ : P
h : ∠ p₁ p₂ p₃ = ∠ p₄ p₅ p₆
h1 : p₂ ≠ p₁
h2 : p₂ ≠ p₃
h3 : p₅ ≠ p₄
h4 : p₅ ≠ p₆
⊢ ∡ p₁ p₂ p₃ = ∡ p₄ p₅ p₆ ∨ ∡ p₁ p₂ p₃ = -∡ p₄ p₅ p₆

Tactic:
have h_1 := EuclideanGeometry.oangle_eq_angle_or_eq_neg_angle h1.symm h2.symm

Goal state after:
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
p₁ p₂ p₃ p₄ p₅ p₆ : P
h : ∠ p₁ p₂ p₃ = ∠ p₄ p₅ p₆
h1 : p₂ ≠ p₁
h2 : p₂ ≠ p₃
h3 : p₅ ≠ p₄
h4 : p₅ ≠ p₆
h_1 : ∡ p₁ p₂ p₃ = ↑(∠ p₁ p₂ p₃) ∨ ∡ p₁ p₂ p₃ = -↑(∠ p₁ p₂ p₃)
⊢ ∡ p₁ p₂ p₃ = ∡ p₄ p₅ p₆ ∨ ∡ p₁ p₂ p₃ = -∡ p₄ p₅ p₆
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
r : ℝ
⊢ (o.oangle x (y + -(r • x))).sign = (o.oangle x y).sign

Tactic:
← neg_smul,

Goal state after:
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
r : ℝ
⊢ (o.oangle x (y + -r • x)).sign = (o.oangle x y).sign
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
r : ℝ
⊢ (o.oangle (x + -(r • y)) y).sign = (o.oangle x y).sign

Tactic:
← neg_smul,

Goal state after:
V : Type u_1
inst✝² : NormedAddCommGroup V
inst✝¹ : InnerProductSpace ℝ V
inst✝ : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
r : ℝ
⊢ (o.oangle (x + -r • y) y).sign = (o.oangle x y).sign
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Affine

Goal state before:
pp: case neg
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
p₁ p₂ p₃ p₄ p₅ : P
hp₁p₂ : p₁ ≠ p₂
hp₃p₄ : p₃ ≠ p₄
hc : Collinear ℝ {p₁, p₂, p₃, p₄}
hr : SameRay ℝ (p₂ -ᵥ p₁) (p₄ -ᵥ p₃)
hc₅₁₂ : ¬Collinear ℝ {p₅, p₁, p₂}
s : Set (P × P × P) := (fun x ↦ (↑x.1, p₅, x.2 +ᵥ ↑x.1)) '' Set.univ ×ˢ {v | SameRay ℝ (p₂ -ᵥ p₁) v ∧ v ≠ 0}
⊢ (∡ p₁ p₅ p₂).sign = (∡ p₃ p₅ p₄).sign

Tactic:
have hco : IsConnected s :=
      haveI : ConnectedSpace line[ℝ, p₁, p₂] := AddTorsor.connectedSpace _ _
      (isConnected_univ.prod (isConnected_setOfPred_sameRay_and_ne_zero
        (vsub_ne_zero.2 hp₁p₂.symm))).image _ (by fun_prop)

Goal state after:
case neg
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
p₁ p₂ p₃ p₄ p₅ : P
hp₁p₂ : p₁ ≠ p₂
hp₃p₄ : p₃ ≠ p₄
hc : Collinear ℝ {p₁, p₂, p₃, p₄}
hr : SameRay ℝ (p₂ -ᵥ p₁) (p₄ -ᵥ p₃)
hc₅₁₂ : ¬Collinear ℝ {p₅, p₁, p₂}
s : Set (P × P × P) := (fun x ↦ (↑x.1, p₅, x.2 +ᵥ ↑x.1)) '' Set.univ ×ˢ {v | SameRay ℝ (p₂ -ᵥ p₁) v ∧ v ≠ 0}
hco : IsConnected s
⊢ (∡ p₁ p₅ p₂).sign = (∡ p₃ p₅ p₄).sign
Module: Mathlib.Geometry.Euclidean.Angle.Bisector

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝⁵ : NormedAddCommGroup V
inst✝⁴ : InnerProductSpace ℝ V
inst✝³ : MetricSpace P
inst✝² : NormedAddTorsor V P
p p' : P
s₁ s₂ : AffineSubspace ℝ P
inst✝¹ : s₁.direction.HasOrthogonalProjection
inst✝ : s₂.direction.HasOrthogonalProjection
hp'₁ : p' ∈ s₁
hp'₂ : p' ∈ s₂
this✝ : Nonempty ↥s₁
this : Nonempty ↥s₂
h' : p ∉ s₁ ∧ p ∉ s₂
h :
  Real.arcsin (dist p ↑((orthogonalProjection s₁) p) / dist p p') =
    Real.arcsin (dist p ↑((orthogonalProjection s₂) p) / dist p p')
hp : p ≠ p'
hpd : 0 < dist p p'
⊢ -1 ≤ 0

Tactic:
by norm_num

Goal state after:
Module: Mathlib.Geometry.Euclidean.SignedDist

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
v : V
p q r : P
⊢ ((signedDist v) p) q + ((signedDist v) q) r = ((signedDist v) p) r

Tactic:
simp only [signedDist_apply_apply]
  rw [add_comm, ← inner_add_right, vsub_add_vsub_cancel]

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Affine

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
p₁ p₂ p₃ p₄ : P
h₁₂ : p₁ ≠ p₂
ha : ∡ p₁ p₂ p₃ = ∡ p₃ p₂ p₄
hs : line[ℝ, p₁, p₂].SSameSide p₃ p₄
h₃₂ : p₃ ≠ p₂
h₄₂ : p₄ ≠ p₂
hadd : ∡ p₁ p₂ p₃ + ∡ p₃ p₂ p₄ = ∡ p₁ p₂ p₄
⊢ 2 ≠ 0

Tactic:
by norm_num

Goal state after:
Module: Mathlib.Geometry.Euclidean.Sphere.Basic

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
p₁ p₂ : P
⊢ ∀ p ∈ {p₁, p₂}, dist p (midpoint ℝ p₁ p₂) = ‖2‖⁻¹ * dist p₁ p₂

Tactic:
rintro p (rfl | rfl | _)

Goal state after:
case inl
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
p₂ p : P
⊢ dist p (midpoint ℝ p p₂) = ‖2‖⁻¹ * dist p p₂

case inr
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
p₁ p₂ : P
⊢ dist p₂ (midpoint ℝ p₁ p₂) = ‖2‖⁻¹ * dist p₁ p₂
Module: Mathlib.Geometry.Euclidean.Angle.Bisector

Goal state before:
pp: case inr.inr
V : Type u_1
P : Type u_2
inst✝⁵ : NormedAddCommGroup V
inst✝⁴ : InnerProductSpace ℝ V
inst✝³ : MetricSpace P
inst✝² : NormedAddTorsor V P
inst✝¹ : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
p p' : P
s₁ s₂ : AffineSubspace ℝ P
hp'₁ : p' ∈ s₁
hp'₂ : p' ∈ s₂
hne : ↑((orthogonalProjection s₁) p) ≠ ↑((orthogonalProjection s₂) p)
this✝¹ : Nonempty ↥s₁
this✝ : Nonempty ↥s₂
this : Nonempty ↥(s₁ ⊓ s₂)
hp₁ : ↑((orthogonalProjection s₁) p) ≠ p'
hp₂ : ↑((orthogonalProjection s₂) p) ≠ p'
hc : ¬Collinear ℝ {p', ↑((orthogonalProjection s₁) p), ↑((orthogonalProjection s₂) p)}
h : Wbtw ℝ p' ↑((orthogonalProjection s₂) p) ↑((orthogonalProjection s₁) p)
h' : Collinear ℝ {p', ↑((orthogonalProjection s₁) p), ↑((orthogonalProjection s₂) p)}
⊢ False

Tactic:
exact hc h'

Goal state after:
Module: Mathlib.Geometry.Euclidean.Sphere.Basic

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Sphere P
p₁ p₂ : P
x✝ : p₁ ∈ s ∧ p₂ ∈ s ∧ dist p₁ p₂ = 2 * s.radius
h₁ : p₁ ∈ s
h₂ : p₂ ∈ s
hr : dist p₁ p₂ = 2 * s.radius
⊢ midpoint ℝ p₁ p₂ = s.center

Tactic:
midpoint_eq_iff,

Goal state after:
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Sphere P
p₁ p₂ : P
x✝ : p₁ ∈ s ∧ p₂ ∈ s ∧ dist p₁ p₂ = 2 * s.radius
h₁ : p₁ ∈ s
h₂ : p₂ ∈ s
hr : dist p₁ p₂ = 2 * s.radius
⊢ (AffineEquiv.pointReflection ℝ s.center) p₁ = p₂
Module: Mathlib.Geometry.Euclidean.Sphere.OrthRadius

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Sphere P
p q : P
h : Metric.sphere s.center s.radius ∩ ↑(s.orthRadius p) = {q}
hq : q ∈ Metric.sphere s.center s.radius ∩ ↑(s.orthRadius p)
hr : 0 ≤ s.radius
h' : ∀ (q' : P), q' -ᵥ p ∈ (ℝ ∙ (p -ᵥ s.center))ᗮ ∧ ‖q' -ᵥ p‖ ^ 2 = s.radius ^ 2 - dist p s.center ^ 2 ↔ q' = q
hq' : q -ᵥ p ∈ (ℝ ∙ (p -ᵥ s.center))ᗮ ∧ ‖q -ᵥ p‖ ^ 2 = s.radius ^ 2 - dist p s.center ^ 2
hq'' : (-(q -ᵥ p) +ᵥ p) -ᵥ p ∈ (ℝ ∙ (p -ᵥ s.center))ᗮ ∧ ‖(-(q -ᵥ p) +ᵥ p) -ᵥ p‖ ^ 2 = s.radius ^ 2 - dist p s.center ^ 2
hqq : 2 • (q -ᵥ p) = 0
⊢ 2 ≠ 0

Tactic:
by norm_num

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Incenter

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
t : Triangle ℝ P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
p : P
⊢ dist p ↑((faceOpposite t i₃).orthogonalProjectionSpan p) = dist p ↑((faceOpposite t i₂).orthogonalProjectionSpan p) ↔
    2 • ∡ (t.points i₂) (t.points i₁) p = 2 • ∡ p (t.points i₁) (t.points i₃)

Tactic:
have ha : AffineIndependent ℝ ![t.points i₁, t.points i₂, t.points i₃] := by
    convert!
      t.independent.comp_embedding
        ⟨![i₁, i₂, i₃], by
          intro i j hij
          fin_cases i <;> fin_cases j <;> simp_all⟩
    ext i
    fin_cases i <;> rfl

Goal state after:
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
t : Triangle ℝ P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
p : P
ha : AffineIndependent ℝ ![t.points i₁, t.points i₂, t.points i₃]
⊢ dist p ↑((faceOpposite t i₃).orthogonalProjectionSpan p) = dist p ↑((faceOpposite t i₂).orthogonalProjectionSpan p) ↔
    2 • ∡ (t.points i₂) (t.points i₁) p = 2 • ∡ p (t.points i₁) (t.points i₃)
Module: Mathlib.Geometry.Euclidean.Angle.Incenter

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
t : Triangle ℝ P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
signs : Finset (Fin 3)
⊢ 2 • ∡ (t.points i₂) (t.points i₁) (excenter t signs) = 2 • ∡ (excenter t signs) (t.points i₁) (t.points i₃)

Tactic:
rw [← dist_orthogonalProjectionSpan_faceOpposite_eq_iff_two_zsmul_oangle_eq h₁₂ h₁₃ h₂₃,
    ← touchpoint, ← touchpoint, (t.excenterExists signs).dist_excenter_eq_dist_excenter]

Goal state after:
Module: Mathlib.Geometry.Euclidean.Sphere.Tangent

Goal state before:
pp: case pos
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s₁ s₂ : Sphere P
h : dist s₁.center s₂.center = s₁.radius + s₂.radius
h₁ : 0 ≤ s₁.radius
h₂ : 0 ≤ s₂.radius
h0 : s₁.radius + s₂.radius = 0
⊢ s₁.IsExtTangentAt s₂ ((AffineMap.lineMap s₁.center s₂.center) (s₁.radius / (s₁.radius + s₂.radius)))

pp: case neg
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s₁ s₂ : Sphere P
h : dist s₁.center s₂.center = s₁.radius + s₂.radius
h₁ : 0 ≤ s₁.radius
h₂ : 0 ≤ s₂.radius
h0 : ¬s₁.radius + s₂.radius = 0
⊢ s₁.IsExtTangentAt s₂ ((AffineMap.lineMap s₁.center s₂.center) (s₁.radius / (s₁.radius + s₂.radius)))

Tactic:
· simp only [h0, div_zero, AffineMap.lineMap_apply_zero, isExtTangentAt_center_iff, mem_sphere]
      exact ⟨by linarith, by linarith⟩

Goal state after:
case neg
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s₁ s₂ : Sphere P
h : dist s₁.center s₂.center = s₁.radius + s₂.radius
h₁ : 0 ≤ s₁.radius
h₂ : 0 ≤ s₂.radius
h0 : ¬s₁.radius + s₂.radius = 0
⊢ s₁.IsExtTangentAt s₂ ((AffineMap.lineMap s₁.center s₂.center) (s₁.radius / (s₁.radius + s₂.radius)))
Module: Mathlib.Geometry.Euclidean.Sphere.Tangent

Goal state before:
pp: case neg.refine_3.refine_2
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s₁ s₂ : Sphere P
h : dist s₁.center s₂.center = s₁.radius + s₂.radius
h₁ : 0 ≤ s₁.radius
h₂ : 0 ≤ s₂.radius
h0 : ¬s₁.radius + s₂.radius = 0
⊢ s₁.radius / (s₁.radius + s₂.radius) ≤ 1

Tactic:
· rw [div_le_one (by positivity)]
          linarith

Goal state after:
Module: Mathlib.Geometry.Euclidean.Sphere.OrthRadius

Goal state before:
pp: case refine_1
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
hf2 : Fact (Module.finrank ℝ V = 2)
s : Sphere P
p : P
hp : dist p s.center ≤ s.radius
hpc : p ≠ s.center
v : V
hv : v ∈ (ℝ ∙ (p -ᵥ s.center))ᗮ
hv1 : ‖v‖ = 1
hr : 0 ≤ s.radius
hv0 : v ≠ 0
hf : ∀ (w : ↥(ℝ ∙ (p -ᵥ s.center))ᗮ), ∃ c, c • ⟨v, hv⟩ = w
hvc : ∀ w ∈ (ℝ ∙ (p -ᵥ s.center))ᗮ, ∃ c, c • v = w
hvp : 0 ≤ s.radius ^ 2 - dist p s.center ^ 2
p' : P
h : p' ∈ Metric.sphere s.center s.radius ∩ ↑(s.orthRadius p)
⊢ p' ∈ {√(s.radius ^ 2 - dist p s.center ^ 2) • v +ᵥ p, -(√(s.radius ^ 2 - dist p s.center ^ 2) • v) +ᵥ p}

Tactic:
rw [← vsub_vadd p' p, Set.mem_insert_iff, Set.mem_singleton_iff, vadd_right_cancel_iff,
      vadd_right_cancel_iff]
    have h' : p' -ᵥ p ∈ (ℝ ∙ (p -ᵥ s.center))ᗮ := by
      rw [← direction_orthRadius, vsub_right_mem_direction_iff_mem (s.self_mem_orthRadius p)]
      exact h.2
    rw [← vsub_vadd p' p, vadd_mem_inter_orthRadius_iff_norm_sq hr h'] at h
    obtain ⟨c, hc⟩ := hvc _ h'
    rw [← hc] at h ⊢
    rw [← neg_smul]
    simp_rw [(smul_left_injective ℝ hv0).eq_iff, ← sq_eq_sq_iff_eq_or_eq_neg, Real.sq_sqrt hvp]
    simpa [norm_smul, hv1] using h

Goal state after:
Module: Mathlib.Geometry.Euclidean.Angle.Incenter

Goal state before:
pp: case inl
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
t : Triangle ℝ P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
signs : Finset (Fin 3)
h₁ : ∡ (t.points i₂) (t.points i₁) (excenter t signs) = ∡ (excenter t signs) (t.points i₁) (t.points i₃)
h₂ : ∡ (t.points i₃) (t.points i₂) (excenter t signs) = ∡ (excenter t signs) (t.points i₂) (t.points i₁) + ↑π
h₂' : excenter t signs = excenter t {i₃} ∨ excenter t signs = excenter t {i₁}
h₁' : excenter t signs = incenter t
⊢ excenter t signs = excenter t {i₁}

pp: case inr
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
t : Triangle ℝ P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
signs : Finset (Fin 3)
h₁ : ∡ (t.points i₂) (t.points i₁) (excenter t signs) = ∡ (excenter t signs) (t.points i₁) (t.points i₃)
h₂ : ∡ (t.points i₃) (t.points i₂) (excenter t signs) = ∡ (excenter t signs) (t.points i₂) (t.points i₁) + ↑π
h₂' : excenter t signs = excenter t {i₃} ∨ excenter t signs = excenter t {i₁}
h₁' : excenter t signs = excenter t {i₁}
⊢ excenter t signs = excenter t {i₁}

Tactic:
· rcases h₂' with h₂' | h₂'
    · rw [h₁'] at h₂'
      exfalso
      exact (t.excenter_singleton_ne_incenter _).symm h₂'
    · exact h₂'

Goal state after:
case inr
V : Type u_1
P : Type u_2
inst✝⁴ : NormedAddCommGroup V
inst✝³ : InnerProductSpace ℝ V
inst✝² : MetricSpace P
inst✝¹ : NormedAddTorsor V P
hd2 : Fact (finrank ℝ V = 2)
inst✝ : Oriented ℝ V (Fin 2)
t : Triangle ℝ P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
signs : Finset (Fin 3)
h₁ : ∡ (t.points i₂) (t.points i₁) (excenter t signs) = ∡ (excenter t signs) (t.points i₁) (t.points i₃)
h₂ : ∡ (t.points i₃) (t.points i₂) (excenter t signs) = ∡ (excenter t signs) (t.points i₂) (t.points i₁) + ↑π
h₂' : excenter t signs = excenter t {i₃} ∨ excenter t signs = excenter t {i₁}
h₁' : excenter t signs = excenter t {i₁}
⊢ excenter t signs = excenter t {i₁}