Theorem: sbtw_of_sbtw_of_sbtw_of_mem_affineSpan_pair
File: Mathlib/Analysis/Convex/Between.lean

Proof steps:
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
⊢ Sbtw R (t.points i₁) p p₁
state_after: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
⊢ Sbtw R (t.points i₁) p p₁
tactic: have h₁₃ : i₁ ≠ i₃ := by
    rintro rfl
    simp at h₂
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
⊢ Sbtw R (t.points i₁) p p₁
state_after: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
⊢ Sbtw R (t.points i₁) p p₁
tactic: have h₂₃ : i₂ ≠ i₃ := by
    rintro rfl
    simp at h₁
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
⊢ Sbtw R (t.points i₁) p p₁
state_after: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
⊢ Sbtw R (t.points i₁) p p₁
tactic: have h3 : ∀ i : Fin 3, i = i₁ ∨ i = i₂ ∨ i = i₃ := by
    clear h₁ h₂ h₁' h₂'
    -- Porting note: Originally `decide!`
    intro i
    fin_cases i <;> fin_cases i₁ <;> fin_cases i₂ <;> fin_cases i₃ <;> simp at h₁₂ h₁₃ h₂₃ ⊢
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
⊢ Sbtw R (t.points i₁) p p₁
state_after: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
⊢ Sbtw R (t.points i₁) p p₁
tactic: have hu : (Finset.univ : Finset (Fin 3)) = {i₁, i₂, i₃} := by
    clear h₁ h₂ h₁' h₂'
    -- Porting note: Originally `decide!`
    fin_cases i₁ <;> fin_cases i₂ <;> fin_cases i₃
      <;> simp (config := {decide := true}) at h₁₂ h₁₃ h₂₃ ⊢
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
⊢ Sbtw R (t.points i₁) p p₁
state_after: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
⊢ Sbtw R (t.points i₁) p p₁
tactic: have hp : p ∈ affineSpan R (Set.range t.points) := by
    have hle : line[R, t.points i₁, p₁] ≤ affineSpan R (Set.range t.points) := by
      refine affineSpan_pair_le_of_mem_of_mem (mem_affineSpan R (Set.mem_range_self _)) ?_
      have hle : line[R, t.points i₂, t.points i₃] ≤ affineSpan R (Set.range t.points) := by
        refine affineSpan_mono R ?_
        simp [Set.insert_subset_iff]
      rw [AffineSubspace.le_def'] at hle
      exact hle _ h₁.wbtw.mem_affineSpan
    rw [AffineSubspace.le_def'] at hle
    exact hle _ h₁'
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
⊢ Sbtw R (t.points i₁) p p₁
state_after: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
h₁i : p₁ ∈ ⇑(lineMap (t.points i₂) (t.points i₃)) '' Set.Ioo 0 1
⊢ Sbtw R (t.points i₁) p p₁
tactic: have h₁i := h₁.mem_image_Ioo
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
h₁i : p₁ ∈ ⇑(lineMap (t.points i₂) (t.points i₃)) '' Set.Ioo 0 1
⊢ Sbtw R (t.points i₁) p p₁
state_after: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
h₁i : p₁ ∈ ⇑(lineMap (t.points i₂) (t.points i₃)) '' Set.Ioo 0 1
h₂i : p₂ ∈ ⇑(lineMap (t.points i₁) (t.points i₃)) '' Set.Ioo 0 1
⊢ Sbtw R (t.points i₁) p p₁
tactic: have h₂i := h₂.mem_image_Ioo
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
h₁i : p₁ ∈ ⇑(lineMap (t.points i₂) (t.points i₃)) '' Set.Ioo 0 1
h₂i : p₂ ∈ ⇑(lineMap (t.points i₁) (t.points i₃)) '' Set.Ioo 0 1
⊢ Sbtw R (t.points i₁) p p₁
state_after: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
h₁i : ∃ x ∈ Set.Ioo 0 1, (lineMap (t.points i₂) (t.points i₃)) x = p₁
h₂i : ∃ x ∈ Set.Ioo 0 1, (lineMap (t.points i₁) (t.points i₃)) x = p₂
⊢ Sbtw R (t.points i₁) p p₁
tactic: rw [Set.mem_image] at h₁i h₂i
state_before: R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₁ p₂ p : P
h₁ : Sbtw R (t.points i₂) p₁ (t.points i₃)
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, p₁}
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
h₁i : ∃ x ∈ Set.Ioo 0 1, (lineMap (t.points i₂) (t.points i₃)) x = p₁
h₂i : ∃ x ∈ Set.Ioo 0 1, (lineMap (t.points i₁) (t.points i₃)) x = p₂
⊢ Sbtw R (t.points i₁) p p₁
state_after: case intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₂ p : P
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
h₂i : ∃ x ∈ Set.Ioo 0 1, (lineMap (t.points i₁) (t.points i₃)) x = p₂
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
⊢ Sbtw R (t.points i₁) p ((lineMap (t.points i₂) (t.points i₃)) r₁)
tactic: rcases h₁i with ⟨r₁, ⟨hr₁0, hr₁1⟩, rfl⟩
state_before: case intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p₂ p : P
h₂ : Sbtw R (t.points i₁) p₂ (t.points i₃)
h₂' : p ∈ affineSpan R {t.points i₂, p₂}
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
h₂i : ∃ x ∈ Set.Ioo 0 1, (lineMap (t.points i₁) (t.points i₃)) x = p₂
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
⊢ Sbtw R (t.points i₁) p ((lineMap (t.points i₂) (t.points i₃)) r₁)
state_after: case intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p : P
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
h₂' : p ∈ affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
⊢ Sbtw R (t.points i₁) p ((lineMap (t.points i₂) (t.points i₃)) r₁)
tactic: rcases h₂i with ⟨r₂, ⟨hr₂0, hr₂1⟩, rfl⟩
state_before: case intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
p : P
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
hp : p ∈ affineSpan R (Set.range t.points)
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
h₁' : p ∈ affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
h₂' : p ∈ affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
⊢ Sbtw R (t.points i₁) p ((lineMap (t.points i₂) (t.points i₃)) r₁)
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
⊢ Sbtw R (t.points i₁) ((Finset.affineCombination R Finset.univ t.points) w) ((lineMap (t.points i₂) (t.points i₃)) r₁)
tactic: rcases eq_affineCombination_of_mem_affineSpan_of_fintype hp with ⟨w, hw, rfl⟩
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
⊢ Sbtw R (t.points i₁) ((Finset.affineCombination R Finset.univ t.points) w) ((lineMap (t.points i₂) (t.points i₃)) r₁)
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
⊢ Sbtw R (t.points i₁) ((Finset.affineCombination R Finset.univ t.points) w) ((lineMap (t.points i₂) (t.points i₃)) r₁)
tactic: have h₁s :=
    sign_eq_of_affineCombination_mem_affineSpan_single_lineMap t.independent hw (Finset.mem_univ _)
      (Finset.mem_univ _) (Finset.mem_univ _) h₁₂ h₁₃ h₂₃ hr₁0 hr₁1 h₁'
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
⊢ Sbtw R (t.points i₁) ((Finset.affineCombination R Finset.univ t.points) w) ((lineMap (t.points i₂) (t.points i₃)) r₁)
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
⊢ Sbtw R (t.points i₁) ((Finset.affineCombination R Finset.univ t.points) w) ((lineMap (t.points i₂) (t.points i₃)) r₁)
tactic: have h₂s :=
    sign_eq_of_affineCombination_mem_affineSpan_single_lineMap t.independent hw (Finset.mem_univ _)
      (Finset.mem_univ _) (Finset.mem_univ _) h₁₂.symm h₂₃ h₁₃ hr₂0 hr₂1 h₂'
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₁, (lineMap (t.points i₂) (t.points i₃)) r₁}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
⊢ Sbtw R (t.points i₁) ((Finset.affineCombination R Finset.univ t.points) w) ((lineMap (t.points i₂) (t.points i₃)) r₁)
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
⊢ Sbtw R ((Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁))
    ((Finset.affineCombination R Finset.univ t.points) w)
    ((Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁))
tactic: rw [← Finset.univ.affineCombination_affineCombinationSingleWeights R t.points
      (Finset.mem_univ i₁),
    ← Finset.univ.affineCombination_affineCombinationLineMapWeights t.points (Finset.mem_univ _)
      (Finset.mem_univ _)] at h₁' ⊢
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
⊢ Sbtw R ((Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁))
    ((Finset.affineCombination R Finset.univ t.points) w)
    ((Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁))
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
⊢ Sbtw R (Finset.affineCombinationSingleWeights R i₁ i₁) (w i₁) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁ i₁)
tactic: refine
    Sbtw.affineCombination_of_mem_affineSpan_pair t.independent hw
      (Finset.univ.sum_affineCombinationSingleWeights R (Finset.mem_univ _))
      (Finset.univ.sum_affineCombinationLineMapWeights (Finset.mem_univ _) (Finset.mem_univ _) _)
      h₁' (Finset.mem_univ i₁) ?_
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
⊢ Sbtw R (Finset.affineCombinationSingleWeights R i₁ i₁) (w i₁) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁ i₁)
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
⊢ w i₁ ∈ Set.Ioo 0 1
tactic: rw [Finset.affineCombinationSingleWeights_apply_self,
    Finset.affineCombinationLineMapWeights_apply_of_ne h₁₂ h₁₃, sbtw_one_zero_iff]
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), SignType.sign (w i) = SignType.sign (w i₃)
⊢ w i₁ ∈ Set.Ioo 0 1
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), SignType.sign (w i) = SignType.sign (w i₃)
hss : SignType.sign (∑ i : Fin (2 + 1), w i) = 1
⊢ w i₁ ∈ Set.Ioo 0 1
tactic: have hss : SignType.sign (∑ i, w i) = 1 := by simp [hw]
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), SignType.sign (w i) = SignType.sign (w i₃)
hss : SignType.sign (∑ i : Fin (2 + 1), w i) = 1
⊢ w i₁ ∈ Set.Ioo 0 1
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), SignType.sign (w i) = SignType.sign (w i₃)
hss : SignType.sign (∑ i : Fin (2 + 1), w i) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
⊢ w i₁ ∈ Set.Ioo 0 1
tactic: have hs' := sign_sum Finset.univ_nonempty (SignType.sign (w i₃)) fun i _ => hs i
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), SignType.sign (w i) = SignType.sign (w i₃)
hss : SignType.sign (∑ i : Fin (2 + 1), w i) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
⊢ w i₁ ∈ Set.Ioo 0 1
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), SignType.sign (w i) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
⊢ w i₁ ∈ Set.Ioo 0 1
tactic: rw [hs'] at hss
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), SignType.sign (w i) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
⊢ w i₁ ∈ Set.Ioo 0 1
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ w i₁ ∈ Set.Ioo 0 1
tactic: simp_rw [hss, sign_eq_one_iff] at hs
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ w i₁ ∈ Set.Ioo 0 1
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ w i₁ < 1
tactic: refine ⟨hs i₁, ?_⟩
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i : Fin (2 + 1), w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ w i₁ < 1
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i ∈ {i₁, i₂, i₃}, w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ w i₁ < 1
tactic: rw [hu] at hw
state_before: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i ∈ {i₁, i₂, i₃}, w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ w i₁ < 1
state_after: case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : w i₁ + (w i₂ + w i₃) = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ w i₁ < 1

case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : w i₁ + ∑ x ∈ {i₂, i₃}, w x = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ i₂ ∉ {i₃}

case intro.intro.intro.intro.intro.intro.intro.intro
R : Type u_1
V : Type u_2
V' : Type u_3
P : Type u_4
P' : Type u_5
inst✝⁴ : LinearOrderedRing R
inst✝³ : AddCommGroup V
inst✝² : Module R V
inst✝¹ : AddTorsor V P
inst✝ : NoZeroSMulDivisors R V
t : Affine.Triangle R P
i₁ i₂ i₃ : Fin 3
h₁₂ : i₁ ≠ i₂
this : DecidableRel fun x x_1 => x < x_1 := LinearOrderedRing.decidableLT
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
h3 : ∀ (i : Fin 3), i = i₁ ∨ i = i₂ ∨ i = i₃
hu : Finset.univ = {i₁, i₂, i₃}
r₁ : R
hr₁0 : 0 < r₁
hr₁1 : r₁ < 1
h₁ : Sbtw R (t.points i₂) ((lineMap (t.points i₂) (t.points i₃)) r₁) (t.points i₃)
r₂ : R
hr₂0 : 0 < r₂
hr₂1 : r₂ < 1
h₂ : Sbtw R (t.points i₁) ((lineMap (t.points i₁) (t.points i₃)) r₂) (t.points i₃)
w : Fin (2 + 1) → R
hw : ∑ i ∈ {i₁, i₂, i₃}, w i = 1
hp : (Finset.affineCombination R Finset.univ t.points) w ∈ affineSpan R (Set.range t.points)
h₁' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R
      {(Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationSingleWeights R i₁),
        (Finset.affineCombination R Finset.univ t.points) (Finset.affineCombinationLineMapWeights i₂ i₃ r₁)}
h₂' :
  (Finset.affineCombination R Finset.univ t.points) w ∈
    affineSpan R {t.points i₂, (lineMap (t.points i₁) (t.points i₃)) r₂}
h₁s : SignType.sign (w i₂) = SignType.sign (w i₃)
h₂s : SignType.sign (w i₁) = SignType.sign (w i₃)
hss : SignType.sign (w i₃) = 1
hs' : SignType.sign (∑ i : Fin 3, w i) = SignType.sign (w i₃)
hs : ∀ (i : Fin 3), 0 < w i
⊢ i₁ ∉ {i₂, i₃}
tactic: rw [Finset.sum_insert, Finset.sum_insert, Finset.sum_singleton] at hw