mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Geometry.Euclidean.Angle.Unoriented.Affine

Goal state before:
pp: case refine_2.inl
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
p₁ p₃ : P
⊢ Collinear ℝ {p₁, p₁, p₃}

pp: case refine_2.inr.inl
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
p₁ p₃ : P
⊢ Collinear ℝ {p₁, p₃, p₃}

pp: case refine_2.inr.inr.inl
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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = 0
⊢ Collinear ℝ {p₁, p₂, p₃}

pp: case refine_2.inr.inr.inr
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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = π
⊢ Collinear ℝ {p₁, p₂, p₃}

Tactic:
· simpa using collinear_pair ℝ p₁ p₃

Goal state after:
case refine_2.inr.inl
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
p₁ p₃ : P
⊢ Collinear ℝ {p₁, p₃, p₃}

case refine_2.inr.inr.inl
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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = 0
⊢ Collinear ℝ {p₁, p₂, p₃}

case refine_2.inr.inr.inr
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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = π
⊢ Collinear ℝ {p₁, p₂, p₃}
Module: Mathlib.Geometry.Euclidean.Angle.Unoriented.Affine

Goal state before:
pp: case refine_2.inr.inl
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
p₁ p₃ : P
⊢ Collinear ℝ {p₁, p₃, p₃}

pp: case refine_2.inr.inr.inl
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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = 0
⊢ Collinear ℝ {p₁, p₂, p₃}

pp: case refine_2.inr.inr.inr
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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = π
⊢ Collinear ℝ {p₁, p₂, p₃}

Tactic:
· simpa using collinear_pair ℝ p₁ p₃

Goal state after:
case refine_2.inr.inr.inl
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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = 0
⊢ Collinear ℝ {p₁, p₂, p₃}

case refine_2.inr.inr.inr
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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = π
⊢ Collinear ℝ {p₁, p₂, p₃}
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: case pos.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)
w x y z : V
h : InnerProductGeometry.angle w x = InnerProductGeometry.angle y z
hs : (o.oangle w x).sign = (o.oangle y z).sign
h0 : (w = 0 ∨ x = 0) ∨ y = 0 ∨ z = 0
hswx : (o.oangle w x).sign = 0
hsyz : (o.oangle y z).sign = 0
hwx : InnerProductGeometry.angle w x = π / 2
hyz : InnerProductGeometry.angle y z = π / 2
hpi : π / 2 ≠ π
h0yz : y = 0 ∨ z = 0
h0wx : w = 0
⊢ o.oangle w x = o.oangle y z

Tactic:
rcases h0yz with (h0yz | h0yz)

Goal state after:
case pos.inl.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)
w x y z : V
h : InnerProductGeometry.angle w x = InnerProductGeometry.angle y z
hs : (o.oangle w x).sign = (o.oangle y z).sign
h0 : (w = 0 ∨ x = 0) ∨ y = 0 ∨ z = 0
hswx : (o.oangle w x).sign = 0
hsyz : (o.oangle y z).sign = 0
hwx : InnerProductGeometry.angle w x = π / 2
hyz : InnerProductGeometry.angle y z = π / 2
hpi : π / 2 ≠ π
h0wx : w = 0
h0yz : y = 0
⊢ o.oangle w x = o.oangle y z

case pos.inl.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)
w x y z : V
h : InnerProductGeometry.angle w x = InnerProductGeometry.angle y z
hs : (o.oangle w x).sign = (o.oangle y z).sign
h0 : (w = 0 ∨ x = 0) ∨ y = 0 ∨ z = 0
hswx : (o.oangle w x).sign = 0
hsyz : (o.oangle y z).sign = 0
hwx : InnerProductGeometry.angle w x = π / 2
hyz : InnerProductGeometry.angle y z = π / 2
hpi : π / 2 ≠ π
h0wx : w = 0
h0yz : z = 0
⊢ o.oangle w x = o.oangle y z
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: case pos.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)
w x y z : V
h : InnerProductGeometry.angle w x = InnerProductGeometry.angle y z
hs : (o.oangle w x).sign = (o.oangle y z).sign
h0 : (w = 0 ∨ x = 0) ∨ y = 0 ∨ z = 0
hswx : (o.oangle w x).sign = 0
hsyz : (o.oangle y z).sign = 0
hwx : InnerProductGeometry.angle w x = π / 2
hyz : InnerProductGeometry.angle y z = π / 2
hpi : π / 2 ≠ π
h0yz : y = 0 ∨ z = 0
h0wx : x = 0
⊢ o.oangle w x = o.oangle y z

Tactic:
rcases h0yz with (h0yz | h0yz)

Goal state after:
case pos.inr.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)
w x y z : V
h : InnerProductGeometry.angle w x = InnerProductGeometry.angle y z
hs : (o.oangle w x).sign = (o.oangle y z).sign
h0 : (w = 0 ∨ x = 0) ∨ y = 0 ∨ z = 0
hswx : (o.oangle w x).sign = 0
hsyz : (o.oangle y z).sign = 0
hwx : InnerProductGeometry.angle w x = π / 2
hyz : InnerProductGeometry.angle y z = π / 2
hpi : π / 2 ≠ π
h0wx : x = 0
h0yz : y = 0
⊢ o.oangle w x = o.oangle y z

case pos.inr.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)
w x y z : V
h : InnerProductGeometry.angle w x = InnerProductGeometry.angle y z
hs : (o.oangle w x).sign = (o.oangle y z).sign
h0 : (w = 0 ∨ x = 0) ∨ y = 0 ∨ z = 0
hswx : (o.oangle w x).sign = 0
hsyz : (o.oangle y z).sign = 0
hwx : InnerProductGeometry.angle w x = π / 2
hyz : InnerProductGeometry.angle y z = π / 2
hpi : π / 2 ≠ π
h0wx : x = 0
h0yz : z = 0
⊢ o.oangle w x = o.oangle y z
Module: Mathlib.Geometry.Euclidean.Angle.Unoriented.RightAngle

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
p₁ p₂ p₃ : P
h : ∠ p₁ p₂ p₃ = π / 2
h0 : p₃ ≠ p₂
⊢ ∠ p₂ p₃ p₁ < π / 2

Tactic:
rw [angle, ← inner_eq_zero_iff_angle_eq_pi_div_two, real_inner_comm, ← neg_eq_zero, ←
    inner_neg_left, neg_vsub_eq_vsub_rev] at h
  rw [ne_comm, ← @vsub_ne_zero V] at h0
  rw [angle, ← vsub_add_vsub_cancel p₁ p₂ p₃, add_comm]
  exact angle_add_lt_pi_div_two_of_inner_eq_zero h h0

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
r : ℝ
⊢ ¬LinearIndependent ℝ ![x, r • x + y] ↔ ¬LinearIndependent ℝ ![x, y]

Tactic:
Fintype.not_linearIndependent_iff,

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
⊢ (∃ g, ∑ i, g i • ![x, r • x + y] i = 0 ∧ ∃ i, g i ≠ 0) ↔ ∃ g, ∑ i, g i • ![x, y] i = 0 ∧ ∃ i, g i ≠ 0
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.RightAngle

Goal state before:
pp: V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
hd2 : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
h : o.oangle x y = ↑(π / 2)
hs : (o.oangle y (y - x)).sign = 1
⊢ ‖x‖ / Real.sin (InnerProductGeometry.angle y (y - x)) = ‖y - x‖

Tactic:
InnerProductGeometry.norm_div_sin_angle_sub_of_inner_eq_zero
      (o.inner_rev_eq_zero_of_oangle_eq_pi_div_two h)
      (Or.inr (o.left_ne_zero_of_oangle_eq_pi_div_two h))

Goal state after:
V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
hd2 : Fact (finrank ℝ V = 2)
o : Orientation ℝ V (Fin 2)
x y : V
h : o.oangle x y = ↑(π / 2)
hs : (o.oangle y (y - x)).sign = 1
⊢ ‖y - x‖ = ‖y - x‖
Module: Mathlib.Geometry.Euclidean.Angle.Unoriented.Projection

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
p p' : P
s : AffineSubspace ℝ P
inst✝ : s.direction.HasOrthogonalProjection
h : p' ∈ s
⊢ ∠ p' (↑((orthogonalProjection s) p)) p = π / 2

Tactic:
rw [angle_comm, angle_self_orthogonalProjection p h]

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 p : P
h : p₁ ≠ p₂
hd : ⟪p -ᵥ p₁, p -ᵥ p₁⟫ = ⟪p -ᵥ p₂, p -ᵥ p₂⟫
⊢ ⟪p -ᵥ p₁ - (p -ᵥ p₂), ⅟2 • (p -ᵥ p₁) + ⅟2 • (p -ᵥ p₂)⟫ = 0

Tactic:
inner_sub_left,

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 p : P
h : p₁ ≠ p₂
hd : ⟪p -ᵥ p₁, p -ᵥ p₁⟫ = ⟪p -ᵥ p₂, p -ᵥ p₂⟫
⊢ ⟪p -ᵥ p₁, ⅟2 • (p -ᵥ p₁) + ⅟2 • (p -ᵥ p₂)⟫ - ⟪p -ᵥ p₂, ⅟2 • (p -ᵥ p₁) + ⅟2 • (p -ᵥ p₂)⟫ = 0
Module: Mathlib.Geometry.Euclidean.PerpBisector

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
c p₁ p₂ : P
⊢ ⟪c -ᵥ p₁ - (midpoint ℝ p₁ p₂ -ᵥ p₁), p₂ -ᵥ p₁⟫ = 0 ↔ ⟪c -ᵥ p₁, p₂ -ᵥ p₁⟫ = dist p₁ p₂ ^ 2 / 2

Tactic:
inner_sub_left,

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
c p₁ p₂ : P
⊢ ⟪c -ᵥ p₁, p₂ -ᵥ p₁⟫ - ⟪midpoint ℝ p₁ p₂ -ᵥ p₁, p₂ -ᵥ p₁⟫ = 0 ↔ ⟪c -ᵥ p₁, p₂ -ᵥ p₁⟫ = dist p₁ p₂ ^ 2 / 2
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)
p p₁ p₂ p₃ p₄ : P
hp₁₃ : Sbtw ℝ p₁ p p₃
hp₂₄ : Sbtw ℝ p₂ p p₄
⊢ (∡ p₁ p₄ p₂).sign = (∡ p₁ p₃ p₂).sign

Tactic:
rw [← Sbtw.oangle_eq_right hp₂₄.symm, Sbtw.oangle_sign_eq _ hp₁₃, ← oangle_rotate_sign,
    Sbtw.oangle_sign_eq _ hp₂₄.symm, Sbtw.oangle_eq_left hp₁₃.symm]

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

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝² : NormedAddCommGroup V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Sphere P
p : P
hp : p ∈ s
⊢ ‖p -ᵥ s.center‖ = s.radius

Tactic:
rw [← dist_eq_norm_vsub']; exact mem_sphere'.mp hp

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
s : Sphere P
p₁ p₂ : P
h : s.IsDiameter p₁ p₂
hr : s.radius ≠ 0
⊢ Sbtw ℝ p₁ s.center p₂

Tactic:
rw [← h.midpoint_eq_center]
  exact sbtw_midpoint_of_ne _ (h.left_ne_right_iff_radius_ne_zero.2 hr)

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
s : Sphere P
p q : P
h : s.orthRadius p ≤ s.orthRadius q
h' : (ℝ ∙ (p -ᵥ s.center))ᗮ ≤ (ℝ ∙ (q -ᵥ s.center))ᗮ
r : ℝ
hr : r • (p -ᵥ s.center) = q -ᵥ s.center
hp : ⟪p -ᵥ s.center - r • (p -ᵥ s.center), r • (p -ᵥ s.center)⟫ = 0
⊢ p = q ∨ q = s.center

Tactic:
inner_sub_left,

Goal state after:
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
s : Sphere P
p q : P
h : s.orthRadius p ≤ s.orthRadius q
h' : (ℝ ∙ (p -ᵥ s.center))ᗮ ≤ (ℝ ∙ (q -ᵥ s.center))ᗮ
r : ℝ
hr : r • (p -ᵥ s.center) = q -ᵥ s.center
hp : ⟪p -ᵥ s.center, r • (p -ᵥ s.center)⟫ - ⟪r • (p -ᵥ s.center), r • (p -ᵥ s.center)⟫ = 0
⊢ p = q ∨ q = s.center
Module: Mathlib.Geometry.Euclidean.Basic

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
s : AffineSubspace ℝ P
inst✝ : FiniteDimensional ℝ ↥s.direction
hd : finrank ℝ ↥s.direction = 2
c₁ c₂ p₁ p₂ : P
hc₁s : c₁ ∈ s
hc₂s : c₂ ∈ s
hp₁s : p₁ ∈ s
hp₂s : p₂ ∈ s
r₁ r₂ : ℝ
hc : c₁ ≠ c₂
hp : p₁ ≠ p₂
hp₁c₁ : dist p₁ c₁ = r₁
hp₂c₁ : dist p₂ c₁ = r₁
hp₁c₂ : dist p₁ c₂ = r₂
hp₂c₂ : dist p₂ c₂ = r₂
ho : ⟪c₂ -ᵥ c₁, p₂ -ᵥ p₁⟫ = 0
b : Fin 2 → V := ![c₂ -ᵥ c₁, p₂ -ᵥ p₁]
hb : LinearIndependent ℝ b
hbs : Submodule.span ℝ (Set.range b) = s.direction
hv : ∀ v ∈ s.direction, ∃ t₁ t₂, v = t₁ • (c₂ -ᵥ c₁) + t₂ • (p₂ -ᵥ p₁)
t₁ t₂ : ℝ
hop : t₁ = 0
hps : t₂ • (p₂ -ᵥ p₁) +ᵥ p₁ ∈ s
hpc₁ : t₂ = 0 ∨ t₂ = 1
hpc₂ : dist (t₂ • (p₂ -ᵥ p₁) +ᵥ p₁) c₂ = r₂
hp' : p₂ -ᵥ p₁ ≠ 0
hp₂ : 1 = -2 * ⟪p₂ -ᵥ p₁, p₁ -ᵥ c₁⟫ / ⟪p₂ -ᵥ p₁, p₂ -ᵥ p₁⟫
⊢ t₂ • (p₂ -ᵥ p₁) +ᵥ p₁ = p₁ ∨ t₂ • (p₂ -ᵥ p₁) +ᵥ p₁ = p₂

Tactic:
rcases hpc₁ with hpc₁ | hpc₁ <;> simp [hpc₁]

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

Goal state before:
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
s : Sphere P
p₁ p₂ : P
hp₁ : dist p₁ s.center = s.radius
hp₂ : dist p₂ s.center ≤ s.radius
h : ¬p₁ = p₂
⊢ 0 < ⟪p₁ -ᵥ s.center - (p₂ -ᵥ s.center), p₁ -ᵥ s.center⟫

Tactic:
inner_sub_left,

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
s : Sphere P
p₁ p₂ : P
hp₁ : dist p₁ s.center = s.radius
hp₂ : dist p₂ s.center ≤ s.radius
h : ¬p₁ = p₂
⊢ 0 < ⟪p₁ -ᵥ s.center, p₁ -ᵥ s.center⟫ - ⟪p₂ -ᵥ s.center, p₁ -ᵥ s.center⟫
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
⊢ q ∈ s ∧ dist q s.center ^ 2 = dist p s.center ^ 2 + dist q p ^ 2 ↔
    0 ≤ s.radius ∧
      dist q s.center ^ 2 = dist p s.center ^ 2 + dist q p ^ 2 ∧ dist q p ^ 2 = s.radius ^ 2 - dist p s.center ^ 2

Tactic:
nth_rw 3 [and_comm]

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
p q : P
⊢ q ∈ s ∧ dist q s.center ^ 2 = dist p s.center ^ 2 + dist q p ^ 2 ↔
    0 ≤ s.radius ∧
      dist q p ^ 2 = s.radius ^ 2 - dist p s.center ^ 2 ∧ dist q s.center ^ 2 = dist p s.center ^ 2 + dist q p ^ 2
Module: Mathlib.Geometry.Euclidean.Sphere.OrthRadius

Goal state before:
pp: case inr
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 : dist q s.center ^ 2 - dist p s.center ^ 2 = dist q p ^ 2
h0 : s.radius < 0
⊢ q ∈ s ↔ 0 ≤ s.radius ∧ dist q s.center ^ 2 - dist p s.center ^ 2 = s.radius ^ 2 - dist p s.center ^ 2

Tactic:
· simp only [h0.not_ge, sub_left_inj, false_and, iff_false]
    intro hm
    exact h0.not_ge (radius_nonneg_of_mem hm)

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

Goal state before:
pp: case inr.inl
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 : P
h : dist p s.center = s.radius
⊢ {p} = ∅ ↔
    s.radius < dist p s.center ∨
      Module.finrank ℝ V = 1 ∧ dist p s.center < s.radius ∧ p ≠ s.center ∨ Subsingleton V ∧ s.radius ≠ 0

Tactic:
simp only [Set.singleton_ne_empty, h, lt_self_iff_false, ne_eq, false_and, and_false, false_or,
      false_iff, not_and, not_not]

Goal state after:
case inr.inl
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 : P
h : dist p s.center = s.radius
⊢ Subsingleton V → s.radius = 0
Module: Mathlib.Geometry.Euclidean.Incenter

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
m n : ℕ
inst✝¹ : NeZero m
inst✝ : NeZero n
s : Simplex ℝ P n
e : Fin (n + 1) ≃ Fin (m + 1)
signs : Finset (Fin (m + 1))
⊢ (s.reindex e).ExcenterExists signs ↔ s.ExcenterExists (Finset.map e.symm.toEmbedding signs)

Tactic:
by
  simp_rw [ExcenterExists, excenterWeightsUnnorm_reindex, Finset.sum_comp_equiv,
    Finset.map_univ_equiv]

Goal state after:
Module: Mathlib.Geometry.Euclidean.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
n : ℕ
inst✝ : NeZero n
s : Simplex ℝ P n
signs : Finset (Fin (n + 1))
i : Fin (n + 1)
⊢ s.excenterWeightsUnnorm signsᶜ i = (-s.excenterWeightsUnnorm signs) i

Tactic:
by_cases h : i ∈ signs <;> simp [excenterWeightsUnnorm, h]

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

Goal state before:
pp: case e'_2.e'_6
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
n : ℕ
inst✝ : NeZero n
s : Simplex ℝ P n
i : Fin (n + 1)
hi : i ≠ 0
j : Fin (n + 1)
hj : j ∈ (Finset.univ.erase 0).erase i
⊢ ⟪s.points i -ᵥ s.points 0, s.points j -ᵥ s.altitudeFoot j⟫ = 0

Tactic:
← Submodule.mem_orthogonal_singleton_iff_inner_right

Goal state after:
case e'_2.e'_6
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
n : ℕ
inst✝ : NeZero n
s : Simplex ℝ P n
i : Fin (n + 1)
hi : i ≠ 0
j : Fin (n + 1)
hj : j ∈ (Finset.univ.erase 0).erase i
⊢ s.points j -ᵥ s.altitudeFoot j ∈ (ℝ ∙ (s.points i -ᵥ s.points 0))ᗮ
Module: Mathlib.Geometry.Euclidean.Circumcenter

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
s : AffineSubspace ℝ P
inst✝ : s.direction.HasOrthogonalProjection
ps : Set P
p : P
hps : ps ⊆ ↑s
hp : p ∉ s
this : Nonempty ↥s
cc : P
cr : ℝ
hcccru : ∀ (y : Sphere P), y.center ∈ s ∧ ps ⊆ Metric.sphere y.center y.radius → y = { center := cc, radius := cr }
hcc : cc ∈ s
hcr : ps ⊆ Metric.sphere cc cr
x : ℝ := dist cc ↑((orthogonalProjection s) p)
y : ℝ := dist p ↑((orthogonalProjection s) p)
hy0 : y ≠ 0
ycc₂ : ℝ := (x * x + y * y - cr * cr) / (2 * y)
cc₂ : P := (ycc₂ / y) • (p -ᵥ ↑((orthogonalProjection s) p)) +ᵥ cc
cr₂ : ℝ := √(cr * cr + ycc₂ * ycc₂)
hpo : p = 1 • (p -ᵥ ↑((orthogonalProjection s) p)) +ᵥ ↑((orthogonalProjection s) p)
cc₃ : P
cr₃ : ℝ
hcc₃ : cc₃ ∈ affineSpan ℝ (insert p ↑s)
hcr₃ : insert p ps ⊆ Metric.sphere cc₃ cr₃
t₃ : ℝ
hcc₃' : cc ∈ s
hcc₃'' : cc₃ = t₃ • (p -ᵥ ↑((orthogonalProjection s) p)) +ᵥ cc
hcr₃' : ∀ p₁ ∈ ps, dist p₁ ↑⟨cc, hcc₃'⟩ = cr
p0 : P
hp0 : p0 ∈ ps
⊢ cr₃ = √(cr * cr + t₃ * y * (t₃ * y))

Tactic:
have h' : ↑(⟨cc, hcc₃'⟩ : s) = cc := 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
s : AffineSubspace ℝ P
inst✝ : s.direction.HasOrthogonalProjection
ps : Set P
p : P
hps : ps ⊆ ↑s
hp : p ∉ s
this : Nonempty ↥s
cc : P
cr : ℝ
hcccru : ∀ (y : Sphere P), y.center ∈ s ∧ ps ⊆ Metric.sphere y.center y.radius → y = { center := cc, radius := cr }
hcc : cc ∈ s
hcr : ps ⊆ Metric.sphere cc cr
x : ℝ := dist cc ↑((orthogonalProjection s) p)
y : ℝ := dist p ↑((orthogonalProjection s) p)
hy0 : y ≠ 0
ycc₂ : ℝ := (x * x + y * y - cr * cr) / (2 * y)
cc₂ : P := (ycc₂ / y) • (p -ᵥ ↑((orthogonalProjection s) p)) +ᵥ cc
cr₂ : ℝ := √(cr * cr + ycc₂ * ycc₂)
hpo : p = 1 • (p -ᵥ ↑((orthogonalProjection s) p)) +ᵥ ↑((orthogonalProjection s) p)
cc₃ : P
cr₃ : ℝ
hcc₃ : cc₃ ∈ affineSpan ℝ (insert p ↑s)
hcr₃ : insert p ps ⊆ Metric.sphere cc₃ cr₃
t₃ : ℝ
hcc₃' : cc ∈ s
hcc₃'' : cc₃ = t₃ • (p -ᵥ ↑((orthogonalProjection s) p)) +ᵥ cc
hcr₃' : ∀ p₁ ∈ ps, dist p₁ ↑⟨cc, hcc₃'⟩ = cr
p0 : P
hp0 : p0 ∈ ps
h' : ↑⟨cc, hcc₃'⟩ = cc
⊢ cr₃ = √(cr * cr + t₃ * y * (t₃ * y))
Module: Mathlib.Geometry.Euclidean.Triangle

Goal state before:
pp: V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ‖x‖ = ‖y‖
⊢ Real.cos (angle x (x - y)) = Real.cos (angle y (y - x))

Tactic:
cos_angle,

Goal state after:
V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ‖x‖ = ‖y‖
⊢ ⟪x, x - y⟫ / (‖x‖ * ‖x - y‖) = Real.cos (angle y (y - x))
Module: Mathlib.Geometry.Euclidean.Triangle

Goal state before:
pp: V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ‖x‖ = ‖y‖
⊢ ⟪x, x - y⟫ / (‖x‖ * ‖x - y‖) = Real.cos (angle y (y - x))

Tactic:
cos_angle,

Goal state after:
V : Type u_1
inst✝¹ : NormedAddCommGroup V
inst✝ : InnerProductSpace ℝ V
x y : V
h : ‖x‖ = ‖y‖
⊢ ⟪x, x - y⟫ / (‖x‖ * ‖x - y‖) = ⟪y, y - x⟫ / (‖y‖ * ‖y - x‖)
Module: Mathlib.Geometry.Euclidean.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
n : ℕ
inst✝ : NeZero n
s : Simplex ℝ P n
signs : Finset (Fin (n + 1))
h : s.ExcenterExists signs
i : Fin (n + 1)
⊢ (s.signedInfDist i) ((Finset.affineCombination ℝ Finset.univ s.points) (s.excenterWeights signs)) =
    (if i ∈ signs then -1 else 1) * (∑ j, s.excenterWeightsUnnorm signs j)⁻¹

Tactic:
signedInfDist_affineCombination _ _ h.sum_excenterWeights_eq_one,

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
n : ℕ
inst✝ : NeZero n
s : Simplex ℝ P n
signs : Finset (Fin (n + 1))
h : s.ExcenterExists signs
i : Fin (n + 1)
⊢ s.excenterWeights signs i * ‖s.points i -ᵥ ↑((s.faceOpposite i).orthogonalProjectionSpan (s.points i))‖ =
    (if i ∈ signs then -1 else 1) * (∑ j, s.excenterWeightsUnnorm signs j)⁻¹
Module: Mathlib.Geometry.Euclidean.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
n : ℕ
inst✝ : NeZero n
s : Simplex ℝ P n
signs : Finset (Fin (n + 1))
h : s.ExcenterExists signs
i : Fin (n + 1)
⊢ SignType.sign ((s.signedInfDist i) ((Finset.affineCombination ℝ Finset.univ s.points) (s.excenterWeights signs))) =
    SignType.sign (s.excenterWeights signs i)

Tactic:
signedInfDist_affineCombination _ _ h.sum_excenterWeights_eq_one,

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
n : ℕ
inst✝ : NeZero n
s : Simplex ℝ P n
signs : Finset (Fin (n + 1))
h : s.ExcenterExists signs
i : Fin (n + 1)
⊢ SignType.sign
      (s.excenterWeights signs i * ‖s.points i -ᵥ ↑((s.faceOpposite i).orthogonalProjectionSpan (s.points i))‖) =
    SignType.sign (s.excenterWeights signs i)
Module: Mathlib.Geometry.Euclidean.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
n : ℕ
inst✝ : NeZero n
s : Simplex ℝ P n
i : Fin (n + 1)
⊢ SignType.sign ((s.signedInfDist i) s.incenter) = 1

Tactic:
convert! s.excenterExists_empty.sign_signedInfDist_excenter i
  simp

Goal state after: