mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.ModelTheory.Satisfiability

Goal state before:
pp: L : Language
ι : Type u_1
T : ι → L.Theory
h : ∀ (s : Finset ι), IsSatisfiable (⋃ i ∈ s, T i)
⊢ IsFinitelySatisfiable (⋃ i, T i)

Tactic:
intro s hs

Goal state after:
L : Language
ι : Type u_1
T : ι → L.Theory
h : ∀ (s : Finset ι), IsSatisfiable (⋃ i ∈ s, T i)
s : Finset L.Sentence
hs : ↑s ⊆ ⋃ i, T i
⊢ IsSatisfiable ↑s
Module: Mathlib.ModelTheory.Satisfiability

Goal state before:
pp: L : Language
M : Type w'
inst✝¹ : L.Structure M
inst✝ : Infinite M
κ : Cardinal.{w}
h1 : ℵ₀ ≤ κ
h2 : lift.{w, max u v} L.card ≤ lift.{max u v, w} κ
⊢ ∃ N, (M ≅[L] ↑N) ∧ #↑N = κ

Tactic:
obtain ⟨N, NM | MN, hNκ⟩ := exists_elementaryEmbedding_card_eq L M κ h1 h2
  · exact ⟨N, NM.some.elementarilyEquivalent.symm, hNκ⟩
  · exact ⟨N, MN.some.elementarilyEquivalent, hNκ⟩

Goal state after:
Module: Mathlib.FieldTheory.Differential.Liouville

Goal state before:
pp: F : Type u_1
K : Type u_2
inst✝⁹ : Field F
inst✝⁸ : Field K
inst✝⁷ : Differential F
inst✝⁶ : Differential K
inst✝⁵ : Algebra F K
inst✝⁴ : DifferentialAlgebra F K
inst✝³ : CharZero F
inst✝² : FiniteDimensional F K
inst✝¹ : IsGalois F K
a : F
ι : Type
inst✝ : Fintype ι
c : ι → F
hc : ∀ (x : ι), (c x)′ = 0
u : ι → K
v : K
h : ↑a = ∑ x, ↑(c x) * logDeriv (u x) + v′
this : CharZero K
⊢ ∃ ι₀ x c₀, ∃ (_ : ∀ (x : ι₀), (c₀ x)′ = 0), ∃ u₀ v₀, a = ∑ x, c₀ x * logDeriv (u₀ x) + v₀′

Tactic:
let c₀ (i : ι) := (c i) / (Fintype.card (K ≃ₐ[F] K))

Goal state after:
F : Type u_1
K : Type u_2
inst✝⁹ : Field F
inst✝⁸ : Field K
inst✝⁷ : Differential F
inst✝⁶ : Differential K
inst✝⁵ : Algebra F K
inst✝⁴ : DifferentialAlgebra F K
inst✝³ : CharZero F
inst✝² : FiniteDimensional F K
inst✝¹ : IsGalois F K
a : F
ι : Type
inst✝ : Fintype ι
c : ι → F
hc : ∀ (x : ι), (c x)′ = 0
u : ι → K
v : K
h : ↑a = ∑ x, ↑(c x) * logDeriv (u x) + v′
this : CharZero K
c₀ : ι → F := fun i ↦ c i / ↑(Fintype.card Gal(K/F))
⊢ ∃ ι₀ x c₀, ∃ (_ : ∀ (x : ι₀), (c₀ x)′ = 0), ∃ u₀ v₀, a = ∑ x, c₀ x * logDeriv (u₀ x) + v₀′
Module: Mathlib.FieldTheory.Galois.NormalBasis

Goal state before:
pp: case e'_4
K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Finite L
this✝ : Finite K
this : Fintype K
x : L
hx :
  Ideal.span {X ^ finrank K L - 1} =
    (toSpanSingleton K[X] (AEval' (frobeniusAlgHom K L).toLinearMap)
        ((AEval'.of (frobeniusAlgHom K L).toLinearMap) x)).ker
e_1✝ : Fin (X ^ finrank K L - C 1).natDegree = Fin (AdjoinRoot.powerBasis ⋯).dim
i : Fin (X ^ finrank K L - C 1).natDegree
⊢ (⇑(frobeniusAlgEquivOfAlgebraic K L))^[↑(Fin.cast ⋯ i)] x =
    (⇑(AEval'.of (frobeniusAlgHom K L).toLinearMap).symm ∘
        ⇑(liftQ (Ideal.span {X ^ finrank K L - 1})
            (toSpanSingleton K[X] (AEval' (frobeniusAlgHom K L).toLinearMap)
              ((AEval'.of (frobeniusAlgHom K L).toLinearMap) x))
            ⋯))
      (AdjoinRoot.root (X ^ finrank K L - C 1) ^ ↑i)

Tactic:
refine (LinearEquiv.eq_symm_apply _).mpr (.symm <| (liftQ_apply ..).trans ?_)

Goal state after:
case e'_4
K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Finite L
this✝ : Finite K
this : Fintype K
x : L
hx :
  Ideal.span {X ^ finrank K L - 1} =
    (toSpanSingleton K[X] (AEval' (frobeniusAlgHom K L).toLinearMap)
        ((AEval'.of (frobeniusAlgHom K L).toLinearMap) x)).ker
e_1✝ : Fin (X ^ finrank K L - C 1).natDegree = Fin (AdjoinRoot.powerBasis ⋯).dim
i : Fin (X ^ finrank K L - C 1).natDegree
⊢ (toSpanSingleton K[X] (AEval' (frobeniusAlgHom K L).toLinearMap) ((AEval'.of (frobeniusAlgHom K L).toLinearMap) x))
      ((fun x ↦ x ^ ↑i) X) =
    (AEval'.of (frobeniusAlgHom K L).toLinearMap) ((⇑(frobeniusAlgEquivOfAlgebraic K L))^[↑(Fin.cast ⋯ i)] x)
Module: Mathlib.FieldTheory.KummerExtension

Goal state before:
pp: K : Type u
inst✝ : Field K
n m : ℕ
a : K
hm : Irreducible (X ^ m - C a)
hn :
  ∀ (E : Type u) [inst : Field E] [inst_1 : Algebra K E] (x : E),
    minpoly K x = X ^ m - C a → Irreducible (X ^ n - C (AdjoinSimple.gen K x))
hm' : m ≠ 0
⊢ ∀ (E : Type u) [inst : Field E] [inst_1 : Algebra K E] (x : E),
    minpoly K x = X ^ m - C a → Irreducible (Polynomial.map (algebraMap K ↥K⟮x⟯) (X ^ n) - C (AdjoinSimple.gen K x))

Tactic:
simpa only [Polynomial.map_pow, map_X] using hn

Goal state after:
Module: Mathlib.FieldTheory.JacobsonNoether

Goal state before:
pp: D : Type u_1
inst✝¹ : DivisionRing D
inst✝ : Algebra.IsAlgebraic (↥k) D
H : k ≠ ⊤
p : ℕ
hp : ExpChar D p
insep : ∀ (x : D), IsSeparable (↥k) x → x ∈ k
a : D
ha : a ∉ k
ha₀ : a ≠ 0
b : D
hb1 : ((ad (↥k) D) a) b ≠ 0
n : ℕ
hn : 0 < n
c : D := (⇑((ad (↥k) D) a))^[n] b
hb : c ≠ 0 ∧ (⇑((ad (↥k) D) a))^[n + 1] b = 0
hc_def : c = (⇑((ad (↥k) D) a))^[n] b
x✝ : Invertible c := { invOf := c⁻¹, invOf_mul_self := ⋯, mul_invOf_self := ⋯ }
hc : a * c = c * a
d : D := c⁻¹ * a * (⇑((ad (↥k) D) a))^[n - 1] b
hd_def : d = c⁻¹ * a * (⇑((ad (↥k) D) a))^[n - 1] b
hc' : c⁻¹ * a = a * c⁻¹
c_eq : a * (⇑((ad (↥k) D) a))^[n - 1] b - (⇑((ad (↥k) D) a))^[n - 1] b * a = c
eq1 : c⁻¹ * a * (⇑((ad (↥k) D) a))^[n - 1] b - c⁻¹ * (⇑((ad (↥k) D) a))^[n - 1] b * a = 1
deq : a⁻¹ * (a * d - d * a) = a⁻¹ * a
⊢ False

Tactic:
rw [mul_sub, ← mul_assoc, inv_mul_cancel₀ ha₀, one_mul, ← mul_assoc, sub_eq_iff_eq_add] at deq

Goal state after:
D : Type u_1
inst✝¹ : DivisionRing D
inst✝ : Algebra.IsAlgebraic (↥k) D
H : k ≠ ⊤
p : ℕ
hp : ExpChar D p
insep : ∀ (x : D), IsSeparable (↥k) x → x ∈ k
a : D
ha : a ∉ k
ha₀ : a ≠ 0
b : D
hb1 : ((ad (↥k) D) a) b ≠ 0
n : ℕ
hn : 0 < n
c : D := (⇑((ad (↥k) D) a))^[n] b
hb : c ≠ 0 ∧ (⇑((ad (↥k) D) a))^[n + 1] b = 0
hc_def : c = (⇑((ad (↥k) D) a))^[n] b
x✝ : Invertible c := { invOf := c⁻¹, invOf_mul_self := ⋯, mul_invOf_self := ⋯ }
hc : a * c = c * a
d : D := c⁻¹ * a * (⇑((ad (↥k) D) a))^[n - 1] b
hd_def : d = c⁻¹ * a * (⇑((ad (↥k) D) a))^[n - 1] b
hc' : c⁻¹ * a = a * c⁻¹
c_eq : a * (⇑((ad (↥k) D) a))^[n - 1] b - (⇑((ad (↥k) D) a))^[n - 1] b * a = c
eq1 : c⁻¹ * a * (⇑((ad (↥k) D) a))^[n - 1] b - c⁻¹ * (⇑((ad (↥k) D) a))^[n - 1] b * a = 1
deq : d = 1 + a⁻¹ * d * a
⊢ False
Module: Mathlib.FieldTheory.KummerExtension

Goal state before:
pp: case pos
K : Type u
inst✝¹ : Field K
a : K
h : a = 0
hζ : (primitiveRoots 1 K).Nonempty
H : Irreducible (X ^ 1 - C a)
inst✝ : NeZero 1
__spread✝⁻⁰ : ↥(rootsOfUnity 1 K) →* Gal(K[1√a]/K) := autAdjoinRootXPowSubC 1 a
e : Gal(K[1√a]/K)
this✝ : Fact (Irreducible (X ^ 1 - C a))
this : Algebra K K[1√a] := inferInstance
⊢ 1 * root (X ^ 1 - C a) = e (root (X ^ 1 - C a))

Tactic:
(pow_one _).symm.trans (root_X_pow_sub_C_pow 1 a),

Goal state after:
case pos
K : Type u
inst✝¹ : Field K
a : K
h : a = 0
hζ : (primitiveRoots 1 K).Nonempty
H : Irreducible (X ^ 1 - C a)
inst✝ : NeZero 1
__spread✝⁻⁰ : ↥(rootsOfUnity 1 K) →* Gal(K[1√a]/K) := autAdjoinRootXPowSubC 1 a
e : Gal(K[1√a]/K)
this✝ : Fact (Irreducible (X ^ 1 - C a))
this : Algebra K K[1√a] := inferInstance
⊢ 1 * (of (X ^ 1 - C a)) a = e ((of (X ^ 1 - C a)) a)
Module: Mathlib.FieldTheory.KummerExtension

Goal state before:
pp: case adjoin_rootSet'
K : Type u
inst✝ : Field K
n : ℕ
hζ : (primitiveRoots n K).Nonempty
a : K
H : Irreducible (X ^ n - C a)
this✝¹ : Fact (Irreducible (X ^ n - C a))
this✝ : Algebra K K[n√a] := inferInstance
this : n ≠ 0
⊢ root (X ^ n - C a) ∈ (X ^ n - C a).rootSet K[n√a]

Tactic:
mem_rootSet_of_ne (X_pow_sub_C_ne_zero
      (Nat.pos_of_ne_zero this) a),

Goal state after:
case adjoin_rootSet'
K : Type u
inst✝ : Field K
n : ℕ
hζ : (primitiveRoots n K).Nonempty
a : K
H : Irreducible (X ^ n - C a)
this✝¹ : Fact (Irreducible (X ^ n - C a))
this✝ : Algebra K K[n√a] := inferInstance
this : n ≠ 0
⊢ (aeval (root (X ^ n - C a))) (X ^ n - C a) = 0
Module: Mathlib.FieldTheory.KummerExtension

Goal state before:
pp: case adjoin_rootSet'
K : Type u
inst✝ : Field K
n : ℕ
hζ : (primitiveRoots n K).Nonempty
a : K
H : Irreducible (X ^ n - C a)
this✝ : Fact (Irreducible (X ^ n - C a))
this : Algebra K K[n√a] := ⋯
⊢ Algebra.adjoin K ((X ^ n - C a).rootSet K[n√a]) = ⊤

Tactic:
rw [eq_top_iff, ← AdjoinRoot.adjoinRoot_eq_top]
    apply Algebra.adjoin_mono
    have := ne_zero_of_irreducible_X_pow_sub_C H
    rw [Set.singleton_subset_iff, mem_rootSet_of_ne (X_pow_sub_C_ne_zero
      (Nat.pos_of_ne_zero this) a), aeval_def, AdjoinRoot.algebraMap_eq, AdjoinRoot.eval₂_root]

Goal state after:
Module: Mathlib.FieldTheory.Minpoly.ConjRootClass

Goal state before:
pp: K : Type u_1
L : Type u_2
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Algebra.IsAlgebraic K L
c : ConjRootClass K L
⊢ c.minpoly.Monic

Tactic:
by
  induction c
  rw [minpoly_mk]
  exact minpoly.monic (Algebra.IsIntegral.isIntegral _)

Goal state after:
Module: Mathlib.RingTheory.LinearDisjoint

Goal state before:
pp: R : Type u
inst✝⁸ : CommRing R
A : Type v
inst✝⁷ : CommRing A
B : Type w
inst✝⁶ : CommRing B
inst✝⁵ : Algebra R A
inst✝⁴ : Algebra R B
inst✝³ : Flat R A
inst✝² : Flat R B
inst✝¹ : Algebra.Transcendental R A
inst✝ : Algebra.Transcendental R B
H : IsField (A ⊗[R] B)
this✝⁴ : Field (A ⊗[R] B) := H.toField
a : A
b : B
ha : Function.Injective ⇑(algebraMap R A)
hb : Function.Injective ⇑(algebraMap R B)
fa : A →ₐ[R] A ⊗[R] B := Algebra.TensorProduct.includeLeft
fb : B →ₐ[R] A ⊗[R] B := Algebra.TensorProduct.includeRight
hfa : Function.Injective ⇑fa
hfb : Function.Injective ⇑fb
this✝³ : IsDomain A
this✝² : IsDomain B
this✝¹ : IsDomain R
this✝ : Flat R ↥(toSubmodule fa.range)
key1 : Module.rank R ↥(fa.range ⊓ fb.range) ≤ 1
ga : R[X] →ₐ[R] A := aeval a
gb : R[X] →ₐ[R] B := aeval b
gab : R[X] →ₐ[R] A ⊗[R] B := fa.comp ga
hta : Function.Injective ⇑ga
htb : Function.Injective ⇑gb
htab : Function.Injective ⇑gab
algInst✝¹ : Algebra R[X] A := ga.toAlgebra
algInst✝ : Algebra R[X] B := gb.toAlgebra
f : A ⊗[R] B →ₐ[R] A ⊗[R[X]] B := Algebra.TensorProduct.mapOfCompatibleSMul R[X] R R A B
this : Nontrivial (A ⊗[R[X]] B)
hf : Function.Injective ⇑f
⊢ 1 ⊗ₜ[R[X]] b = a ⊗ₜ[R[X]] 1

Tactic:
convert! ← (TensorProduct.smul_tmul (R := R[X]) (R' := R[X]) (M := A) (N := B) X 1 1).symm <;>
      (simp_rw [Algebra.smul_def, mul_one]; exact aeval_X _)

Goal state after:
Module: Mathlib.RingTheory.LinearDisjoint

Goal state before:
pp: R : Type u
S : Type v
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
A B : Subalgebra R S
H : A.LinearDisjoint B
inst✝³ : Free R ↥A
inst✝² : Flat R ↥B
inst✝¹ : Nontrivial R
inst✝ : Nontrivial S
⊢ Module.rank ↥B ↥(Algebra.adjoin ↥B ↑A) = Module.rank R ↥A

Tactic:
← rank_toSubmodule,

Goal state after:
R : Type u
S : Type v
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
A B : Subalgebra R S
H : A.LinearDisjoint B
inst✝³ : Free R ↥A
inst✝² : Flat R ↥B
inst✝¹ : Nontrivial R
inst✝ : Nontrivial S
⊢ Module.rank ↥B ↥(toSubmodule (Algebra.adjoin ↥B ↑A)) = Module.rank R ↥A
Module: Mathlib.FieldTheory.LinearDisjoint

Goal state before:
pp: F : Type u
inst✝⁴ : Field F
A : Type v
inst✝³ : Field A
B : Type w
inst✝² : Field B
inst✝¹ : Algebra F A
inst✝ : Algebra F B
H :
  ∀ (K : Type (max v w)) [inst : Field K] [inst_1 : Algebra F K] (fa : A →ₐ[F] K) (fb : B →ₐ[F] K),
    fa.fieldRange.LinearDisjoint ↥fb.fieldRange
M : Ideal (A ⊗[F] B)
hM : M.IsMaximal
⊢ IsField (A ⊗[F] B)

Tactic:
apply not_imp_not.1 (Ring.ne_bot_of_isMaximal_of_not_isField hM)

Goal state after:
F : Type u
inst✝⁴ : Field F
A : Type v
inst✝³ : Field A
B : Type w
inst✝² : Field B
inst✝¹ : Algebra F A
inst✝ : Algebra F B
H :
  ∀ (K : Type (max v w)) [inst : Field K] [inst_1 : Algebra F K] (fa : A →ₐ[F] K) (fb : B →ₐ[F] K),
    fa.fieldRange.LinearDisjoint ↥fb.fieldRange
M : Ideal (A ⊗[F] B)
hM : M.IsMaximal
⊢ M = ⊥
Module: Mathlib.FieldTheory.PurelyInseparable.PerfectClosure

Goal state before:
pp: F : Type u
E : Type v
inst✝³ : Field F
inst✝² : Field E
inst✝¹ : Algebra F E
q n : ℕ
hF : ExpChar F q
ι : Type u_1
v : ι → E
inst✝ : Algebra.IsSeparable F E
h : Submodule.span F (Set.range v) = ⊤
this :
  Submonoid.closure (Set.range fun x ↦ x ^ q ^ n) =
    (Submonoid.map { toFun := fun x ↦ x ^ q ^ n, map_one' := ⋯, map_mul' := ⋯ } ⊤).copy (Set.range fun x ↦ x ^ q ^ n) ⋯
⊢ Set.range (toSemifield.toDivisionSemiring.toNPow.1 (q ^ n)) ⊆
    ↑(Submodule.span F (Set.range (toSemifield.toDivisionSemiring.toNPow.1 (q ^ n) ∘ v)))

Tactic:
rw [Set.range_comp, ← Set.image_univ]

Goal state after:
F : Type u
E : Type v
inst✝³ : Field F
inst✝² : Field E
inst✝¹ : Algebra F E
q n : ℕ
hF : ExpChar F q
ι : Type u_1
v : ι → E
inst✝ : Algebra.IsSeparable F E
h : Submodule.span F (Set.range v) = ⊤
this :
  Submonoid.closure (Set.range fun x ↦ x ^ q ^ n) =
    (Submonoid.map { toFun := fun x ↦ x ^ q ^ n, map_one' := ⋯, map_mul' := ⋯ } ⊤).copy (Set.range fun x ↦ x ^ q ^ n) ⋯
⊢ toSemifield.toDivisionSemiring.toNPow.1 (q ^ n) '' Set.univ ⊆
    ↑(Submodule.span F (toSemifield.toDivisionSemiring.toNPow.1 (q ^ n) '' Set.range v))
Module: Mathlib.FieldTheory.RatFunc.Degree

Goal state before:
pp: K : Type u
inst✝ : Field K
p : K[X]
⊢ ((algebraMap K[X] K⟮X⟯) p).intDegree = ↑p.natDegree

Tactic:
rw [intDegree, RatFunc.num_algebraMap, RatFunc.denom_algebraMap, Polynomial.natDegree_one,
    Int.ofNat_zero, sub_zero]

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

Goal state before:
pp: K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
⊢ IntermediateField.restrictScalars K (↥E)⟮ X⟯ = ⊤

Tactic:
IntermediateField.restrictScalars_adjoin,

Goal state after:
K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
⊢ IntermediateField.adjoin K (↑E ∪ {X}) = ⊤
Module: Mathlib.FieldTheory.RatFunc.Luroth

Goal state before:
pp: K : Type u_1
inst✝ : Field K
E : IntermediateField K K⟮X⟯
h : E ≠ ⊥
⊢ ((algebraMap K[X] K⟮X⟯) ((Φ E).coeff (φ E).natDegree)).denom = 1

Tactic:
exact denom_algebraMap _

Goal state after:
Module: Mathlib.Geometry.Convex.Cone.Face.Basic

Goal state before:
pp: R : Type u_1
M : Type u_2
inst✝⁴ : Semiring R
inst✝³ : PartialOrder R
inst✝² : IsOrderedRing R
inst✝¹ : AddCommGroup M
inst✝ : Module R M
C F : PointedCone R M
hF : F.IsFaceOf C
x y : M
hx : x ∈ C
hy : y ∈ C
⊢ x + y ∈ F → x ∈ F ∧ y ∈ F

Tactic:
exact fun h ↦ ⟨mem_of_add_mem_left hF hx hy h, mem_of_add_mem_right hF hx hy h⟩

Goal state after:
Module: Mathlib.Geometry.Convex.Cone.Face.Basic

Goal state before:
pp: R : Type u_1
M : Type u_2
inst✝⁴ : Semiring R
inst✝³ : PartialOrder R
inst✝² : IsOrderedRing R
inst✝¹ : AddCommGroup M
inst✝ : Module R M
C F : PointedCone R M
hF : F.IsFaceOf C
x y : M
hx : x ∈ C
hy : y ∈ C
⊢ x + y ∈ F ↔ x ∈ F ∧ y ∈ F

Tactic:
by
  refine ⟨?_, fun ⟨hx, hy⟩ ↦ F.add_mem hx hy⟩
  exact fun h ↦ ⟨mem_of_add_mem_left hF hx hy h, mem_of_add_mem_right hF hx hy h⟩

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

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)
⊢ s.altitudeFoot i ∈ affineSpan ℝ (Set.range s.points)

Tactic:
by
  refine SetLike.le_def.1 (affineSpan_mono _ ?_) (s.altitudeFoot_mem_affineSpan_faceOpposite _)
  simp

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

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
⊢ dist p₁ p₃ = dist p₁ p₂ + dist p₃ p₂

Tactic:
rw [dist_eq_norm_vsub V, dist_eq_norm_vsub V, dist_eq_norm_vsub V, ← vsub_sub_vsub_cancel_right]
  exact norm_sub_eq_add_norm_of_angle_eq_pi 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 z : V
hx : x ≠ 0
hy : y ≠ 0
hz : z ≠ 0
⊢ o.oangle x (-y) + o.oangle y (-z) + o.oangle z (-x) = ↑π

Tactic:
by
  simp_rw [← oangle_neg_left_eq_neg_right, o.oangle_add_cyc3_neg_left hx hy hz]

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)
f : V ≃ₗᵢ[ℝ] ℂ
hf : (map (Fin 2) f.toLinearEquiv) o = Complex.orientation
x y : V
⊢ o.oangle x y = ↑((starRingEnd ℂ) (f x) * f y).arg

Tactic:
rw [← Complex.oangle, ← hf, o.oangle_map]

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)
f : V ≃ₗᵢ[ℝ] ℂ
hf : (map (Fin 2) f.toLinearEquiv) o = Complex.orientation
x y : V
⊢ o.oangle x y = o.oangle (f.symm (f x)) (f.symm (f y))
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 : ⟪p₂ -ᵥ p₃, p₁ -ᵥ p₂⟫ = 0
h0 : p₁ ≠ p₂ ∨ p₃ = p₂
⊢ 0 < ∠ p₂ p₃ p₁

Tactic:
rw [← @vsub_ne_zero V, eq_comm, ← @vsub_eq_zero_iff_eq V, or_comm] at h0

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
p₁ p₂ p₃ : P
h : ⟪p₂ -ᵥ p₃, p₁ -ᵥ p₂⟫ = 0
h0 : p₂ -ᵥ p₃ = 0 ∨ p₁ -ᵥ p₂ ≠ 0
⊢ 0 < ∠ p₂ p₃ p₁
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 p₁' p₂ p₃ : P
h : Collinear ℝ {p₁, p₂, p₁'}
hp₁p₂ : p₁ ≠ p₂
hp₁'p₂ : p₁' ≠ p₂
hp₃p₂ : ¬p₃ = p₂
⊢ 2 • ∡ p₁ p₂ p₃ = 2 • ∡ p₁' p₂ p₃

Tactic:
rcases h.wbtw_or_wbtw_or_wbtw with (hw | hw | hw)

Goal state after:
case neg.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)
p₁ p₁' p₂ p₃ : P
h : Collinear ℝ {p₁, p₂, p₁'}
hp₁p₂ : p₁ ≠ p₂
hp₁'p₂ : p₁' ≠ p₂
hp₃p₂ : ¬p₃ = p₂
hw : Wbtw ℝ p₁ p₂ p₁'
⊢ 2 • ∡ p₁ p₂ p₃ = 2 • ∡ p₁' p₂ p₃

case neg.inr.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)
p₁ p₁' p₂ p₃ : P
h : Collinear ℝ {p₁, p₂, p₁'}
hp₁p₂ : p₁ ≠ p₂
hp₁'p₂ : p₁' ≠ p₂
hp₃p₂ : ¬p₃ = p₂
hw : Wbtw ℝ p₂ p₁' p₁
⊢ 2 • ∡ p₁ p₂ p₃ = 2 • ∡ p₁' p₂ p₃

case neg.inr.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)
p₁ p₁' p₂ p₃ : P
h : Collinear ℝ {p₁, p₂, p₁'}
hp₁p₂ : p₁ ≠ p₂
hp₁'p₂ : p₁' ≠ p₂
hp₃p₂ : ¬p₃ = p₂
hw : Wbtw ℝ p₁' p₁ p₂
⊢ 2 • ∡ p₁ p₂ p₃ = 2 • ∡ p₁' p₂ p₃
Module: Mathlib.Geometry.Euclidean.Angle.Oriented.Basic

Goal state before:
pp: case refine_2
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
m : Fin (Nat.succ 0).succ → ℝ
hm : m 0 ≠ 0 ∨ m 1 ≠ 0
h : m 0 • x + m 1 • y = 0
⊢ ∃ g, g 0 • ![x, r • x + y] 0 + g 1 • ![x, r • x + y] 1 = 0 ∧ (g 0 ≠ 0 ∨ g 1 ≠ 0)

Tactic:
refine ⟨![m 0 - m 1 * r, m 1], ?_⟩

Goal state after:
case refine_2
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
m : Fin (Nat.succ 0).succ → ℝ
hm : m 0 ≠ 0 ∨ m 1 ≠ 0
h : m 0 • x + m 1 • y = 0
⊢ ![m 0 - m 1 * r, m 1] 0 • ![x, r • x + y] 0 + ![m 0 - m 1 * r, m 1] 1 • ![x, r • x + y] 1 = 0 ∧
    (![m 0 - m 1 * r, m 1] 0 ≠ 0 ∨ ![m 0 - m 1 * r, m 1] 1 ≠ 0)
Module: Mathlib.Geometry.Euclidean.Angle.Bisector

Goal state before:
pp: case refine_1
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
h' : p ∈ s₁
this✝ : Nonempty ↥s₁
this : Nonempty ↥s₂
h : p ∈ s₂
⊢ ∠ p p' p = ∠ p p' ↑((orthogonalProjection s₂) p)

Tactic:
orthogonalProjection_eq_self_iff.2 h

Goal state after:
case refine_1
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
h' : p ∈ s₁
this✝ : Nonempty ↥s₁
this : Nonempty ↥s₂
h : p ∈ s₂
⊢ ∠ p p' p = ∠ p p' p
Module: Mathlib.Geometry.Euclidean.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
v : V
p₁ p₂ : P
hv : v ≠ 0
r : ℝ
hvi : ⟪v, v⟫ ≠ 0
⊢ discrim ⟪v, v⟫ (2 * ⟪v, p₁ -ᵥ p₂⟫) 0 = 2 * ⟪v, p₁ -ᵥ p₂⟫ * (2 * ⟪v, p₁ -ᵥ p₂⟫)

Tactic:
discrim

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
v : V
p₁ p₂ : P
hv : v ≠ 0
r : ℝ
hvi : ⟪v, v⟫ ≠ 0
⊢ (2 * ⟪v, p₁ -ᵥ p₂⟫) ^ 2 - 4 * ⟪v, v⟫ * 0 = 2 * ⟪v, p₁ -ᵥ p₂⟫ * (2 * ⟪v, p₁ -ᵥ p₂⟫)
Module: Mathlib.Geometry.Euclidean.Basic

Goal state before:
pp: case refine_2.«0».«0»
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 : P
hc₁s : c₁ ∈ s
hc₂s : c₂ ∈ s
hp₁s : p₁ ∈ s
hp₂s : p₂ ∈ s
hps : p ∈ s
r₁ r₂ : ℝ
hc : c₁ ≠ c₂
hp : p₁ ≠ p₂
hp₁c₁ : dist p₁ c₁ = r₁
hp₂c₁ : dist p₂ c₁ = r₁
hpc₁ : dist p c₁ = r₁
hp₁c₂ : dist p₁ c₂ = r₂
hp₂c₂ : dist p₂ c₂ = r₂
hpc₂ : dist p c₂ = r₂
ho : ⟪c₂ -ᵥ c₁, p₂ -ᵥ p₁⟫ = 0
hop : ⟪c₂ -ᵥ c₁, p -ᵥ p₁⟫ = 0
b : Fin 2 → V := ![c₂ -ᵥ c₁, p₂ -ᵥ p₁]
hij : (fun i ↦ i) ⟨0, ⋯⟩ ≠ (fun i ↦ i) ⟨0, ⋯⟩
⊢ ⟪b ((fun i ↦ i) ⟨0, ⋯⟩), b ((fun i ↦ i) ⟨0, ⋯⟩)⟫ = 0

Tactic:
exact False.elim (hij rfl)

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

Goal state before:
pp: case refine_2.«0».«1»
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 : P
hc₁s : c₁ ∈ s
hc₂s : c₂ ∈ s
hp₁s : p₁ ∈ s
hp₂s : p₂ ∈ s
hps : p ∈ s
r₁ r₂ : ℝ
hc : c₁ ≠ c₂
hp : p₁ ≠ p₂
hp₁c₁ : dist p₁ c₁ = r₁
hp₂c₁ : dist p₂ c₁ = r₁
hpc₁ : dist p c₁ = r₁
hp₁c₂ : dist p₁ c₂ = r₂
hp₂c₂ : dist p₂ c₂ = r₂
hpc₂ : dist p c₂ = r₂
ho : ⟪c₂ -ᵥ c₁, p₂ -ᵥ p₁⟫ = 0
hop : ⟪c₂ -ᵥ c₁, p -ᵥ p₁⟫ = 0
b : Fin 2 → V := ![c₂ -ᵥ c₁, p₂ -ᵥ p₁]
hij : (fun i ↦ i) ⟨0, ⋯⟩ ≠ (fun i ↦ i) ⟨1, ⋯⟩
⊢ ⟪b ((fun i ↦ i) ⟨0, ⋯⟩), b ((fun i ↦ i) ⟨1, ⋯⟩)⟫ = 0

Tactic:
exact False.elim (hij rfl)

Goal state after:
case refine_2.«0».«1»
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 : P
hc₁s : c₁ ∈ s
hc₂s : c₂ ∈ s
hp₁s : p₁ ∈ s
hp₂s : p₂ ∈ s
hps : p ∈ s
r₁ r₂ : ℝ
hc : c₁ ≠ c₂
hp : p₁ ≠ p₂
hp₁c₁ : dist p₁ c₁ = r₁
hp₂c₁ : dist p₂ c₁ = r₁
hpc₁ : dist p c₁ = r₁
hp₁c₂ : dist p₁ c₂ = r₂
hp₂c₂ : dist p₂ c₂ = r₂
hpc₂ : dist p c₂ = r₂
ho : ⟪c₂ -ᵥ c₁, p₂ -ᵥ p₁⟫ = 0
hop : ⟪c₂ -ᵥ c₁, p -ᵥ p₁⟫ = 0
b : Fin 2 → V := ![c₂ -ᵥ c₁, p₂ -ᵥ p₁]
hij : (fun i ↦ i) ⟨0, ⋯⟩ ≠ (fun i ↦ i) ⟨1, ⋯⟩
⊢ ⟪b ((fun i ↦ i) ⟨0, ⋯⟩), b ((fun i ↦ i) ⟨1, ⋯⟩)⟫ = 0