l3lab/ntp-mathlib huggingface dataset:
/-- If distinct points `p₁` and `p₃` lie in `s` but `p₂` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_mem_of_not_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₁p₃ : p₁ ≠ p₃) (hp₁ : p₁ ∈ s) (hp₂ : p₂ ∉ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (1 : Fin 3) 2)]
  

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₁p₃ : p₁ ≠ p₃
hp₁ : p₁ ∈ s
hp₂ : p₂ ∉ s
hp₃ : p₃ ∈ s
⊢ AffineIndependent k (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 1 2))

Next tactic:
convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₁p₃ hp₁ hp₃ hp₂ using 1
/-- If distinct points `p₁` and `p₃` lie in `s` but `p₂` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_mem_of_not_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₁p₃ : p₁ ≠ p₃) (hp₁ : p₁ ∈ s) (hp₂ : p₂ ∉ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (1 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₁p₃ hp₁ hp₃ hp₂ using 1
  

Proof state:
case h.e'_9
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₁p₃ : p₁ ≠ p₃
hp₁ : p₁ ∈ s
hp₂ : p₂ ∉ s
hp₃ : p₃ ∈ s
⊢ ![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 1 2) = ![p₁, p₃, p₂]

Next tactic:
ext x
/-- If distinct points `p₁` and `p₃` lie in `s` but `p₂` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_mem_of_not_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₁p₃ : p₁ ≠ p₃) (hp₁ : p₁ ∈ s) (hp₂ : p₂ ∉ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (1 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₁p₃ hp₁ hp₃ hp₂ using 1
  ext x
  

Proof state:
case h.e'_9.h
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₁p₃ : p₁ ≠ p₃
hp₁ : p₁ ∈ s
hp₂ : p₂ ∉ s
hp₃ : p₃ ∈ s
x : Fin 3
⊢ (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 1 2)) x = Matrix.vecCons p₁ ![p₃, p₂] x

Next tactic:
fin_cases x
/-- If distinct points `p₁` and `p₃` lie in `s` but `p₂` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_mem_of_not_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₁p₃ : p₁ ≠ p₃) (hp₁ : p₁ ∈ s) (hp₂ : p₂ ∉ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (1 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₁p₃ hp₁ hp₃ hp₂ using 1
  ext x
  fin_cases x <;> 

Proof state:
case h.e'_9.h.head
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₁p₃ : p₁ ≠ p₃
hp₁ : p₁ ∈ s
hp₂ : p₂ ∉ s
hp₃ : p₃ ∈ s
⊢ (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 1 2)) { val := 0, isLt := (_ : 0 < 3) } =
    Matrix.vecCons p₁ ![p₃, p₂] { val := 0, isLt := (_ : 0 < 3) }

Next tactic:
rfl
/-- If distinct points `p₁` and `p₃` lie in `s` but `p₂` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_mem_of_not_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₁p₃ : p₁ ≠ p₃) (hp₁ : p₁ ∈ s) (hp₂ : p₂ ∉ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (1 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₁p₃ hp₁ hp₃ hp₂ using 1
  ext x
  fin_cases x <;> 

Proof state:
case h.e'_9.h.tail.head
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₁p₃ : p₁ ≠ p₃
hp₁ : p₁ ∈ s
hp₂ : p₂ ∉ s
hp₃ : p₃ ∈ s
⊢ (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 1 2)) { val := 1, isLt := (_ : (fun a => a < 3) 1) } =
    Matrix.vecCons p₁ ![p₃, p₂] { val := 1, isLt := (_ : (fun a => a < 3) 1) }

Next tactic:
rfl
/-- If distinct points `p₁` and `p₃` lie in `s` but `p₂` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_mem_of_not_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₁p₃ : p₁ ≠ p₃) (hp₁ : p₁ ∈ s) (hp₂ : p₂ ∉ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (1 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₁p₃ hp₁ hp₃ hp₂ using 1
  ext x
  fin_cases x <;> 

Proof state:
case h.e'_9.h.tail.tail.head
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₁p₃ : p₁ ≠ p₃
hp₁ : p₁ ∈ s
hp₂ : p₂ ∉ s
hp₃ : p₃ ∈ s
⊢ (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 1 2)) { val := 2, isLt := (_ : (fun a => (fun a => a < 3) a) 2) } =
    Matrix.vecCons p₁ ![p₃, p₂] { val := 2, isLt := (_ : (fun a => (fun a => a < 3) a) 2) }

Next tactic:
rfl
/-- If distinct points `p₂` and `p₃` lie in `s` but `p₁` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_not_mem_of_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₂p₃ : p₂ ≠ p₃) (hp₁ : p₁ ∉ s) (hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₂p₃ : p₂ ≠ p₃
hp₁ : p₁ ∉ s
hp₂ : p₂ ∈ s
hp₃ : p₃ ∈ s
⊢ AffineIndependent k ![p₁, p₂, p₃]

Next tactic:
rw [← affineIndependent_equiv (Equiv.swap (0 : Fin 3) 2)]
/-- If distinct points `p₂` and `p₃` lie in `s` but `p₁` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_not_mem_of_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₂p₃ : p₂ ≠ p₃) (hp₁ : p₁ ∉ s) (hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (0 : Fin 3) 2)]
  

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₂p₃ : p₂ ≠ p₃
hp₁ : p₁ ∉ s
hp₂ : p₂ ∈ s
hp₃ : p₃ ∈ s
⊢ AffineIndependent k (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 0 2))

Next tactic:
convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₂p₃.symm hp₃ hp₂ hp₁ using 1
/-- If distinct points `p₂` and `p₃` lie in `s` but `p₁` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_not_mem_of_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₂p₃ : p₂ ≠ p₃) (hp₁ : p₁ ∉ s) (hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (0 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₂p₃.symm hp₃ hp₂ hp₁ using 1
  

Proof state:
case h.e'_9
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₂p₃ : p₂ ≠ p₃
hp₁ : p₁ ∉ s
hp₂ : p₂ ∈ s
hp₃ : p₃ ∈ s
⊢ ![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 0 2) = ![p₃, p₂, p₁]

Next tactic:
ext x
/-- If distinct points `p₂` and `p₃` lie in `s` but `p₁` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_not_mem_of_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₂p₃ : p₂ ≠ p₃) (hp₁ : p₁ ∉ s) (hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (0 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₂p₃.symm hp₃ hp₂ hp₁ using 1
  ext x
  

Proof state:
case h.e'_9.h
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₂p₃ : p₂ ≠ p₃
hp₁ : p₁ ∉ s
hp₂ : p₂ ∈ s
hp₃ : p₃ ∈ s
x : Fin 3
⊢ (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 0 2)) x = Matrix.vecCons p₃ ![p₂, p₁] x

Next tactic:
fin_cases x
/-- If distinct points `p₂` and `p₃` lie in `s` but `p₁` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_not_mem_of_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₂p₃ : p₂ ≠ p₃) (hp₁ : p₁ ∉ s) (hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (0 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₂p₃.symm hp₃ hp₂ hp₁ using 1
  ext x
  fin_cases x <;> 

Proof state:
case h.e'_9.h.head
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₂p₃ : p₂ ≠ p₃
hp₁ : p₁ ∉ s
hp₂ : p₂ ∈ s
hp₃ : p₃ ∈ s
⊢ (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 0 2)) { val := 0, isLt := (_ : 0 < 3) } =
    Matrix.vecCons p₃ ![p₂, p₁] { val := 0, isLt := (_ : 0 < 3) }

Next tactic:
rfl
/-- If distinct points `p₂` and `p₃` lie in `s` but `p₁` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_not_mem_of_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₂p₃ : p₂ ≠ p₃) (hp₁ : p₁ ∉ s) (hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (0 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₂p₃.symm hp₃ hp₂ hp₁ using 1
  ext x
  fin_cases x <;> 

Proof state:
case h.e'_9.h.tail.head
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₂p₃ : p₂ ≠ p₃
hp₁ : p₁ ∉ s
hp₂ : p₂ ∈ s
hp₃ : p₃ ∈ s
⊢ (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 0 2)) { val := 1, isLt := (_ : (fun a => a < 3) 1) } =
    Matrix.vecCons p₃ ![p₂, p₁] { val := 1, isLt := (_ : (fun a => a < 3) 1) }

Next tactic:
rfl
/-- If distinct points `p₂` and `p₃` lie in `s` but `p₁` does not, the three points are affinely
independent. -/
theorem affineIndependent_of_ne_of_not_mem_of_mem_of_mem {s : AffineSubspace k P} {p₁ p₂ p₃ : P}
    (hp₂p₃ : p₂ ≠ p₃) (hp₁ : p₁ ∉ s) (hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) :
    AffineIndependent k ![p₁, p₂, p₃] := by
  rw [← affineIndependent_equiv (Equiv.swap (0 : Fin 3) 2)]
  convert affineIndependent_of_ne_of_mem_of_mem_of_not_mem hp₂p₃.symm hp₃ hp₂ hp₁ using 1
  ext x
  fin_cases x <;> 

Proof state:
case h.e'_9.h.tail.tail.head
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : DivisionRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
s : AffineSubspace k P
p₁ p₂ p₃ : P
hp₂p₃ : p₂ ≠ p₃
hp₁ : p₁ ∉ s
hp₂ : p₂ ∈ s
hp₃ : p₃ ∈ s
⊢ (![p₁, p₂, p₃] ∘ ⇑(Equiv.swap 0 2)) { val := 2, isLt := (_ : (fun a => (fun a => a < 3) a) 2) } =
    Matrix.vecCons p₃ ![p₂, p₁] { val := 2, isLt := (_ : (fun a => (fun a => a < 3) a) 2) }

Next tactic:
rfl
/-- Given an affinely independent family of points, suppose that an affine combination lies in
the span of two points given as affine combinations, and suppose that, for two indices, the
coefficients in the first point in the span are zero and those in the second point in the span
have the same sign. Then the coefficients in the combination lying in the span have the same
sign. -/
theorem sign_eq_of_affineCombination_mem_affineSpan_pair {p : ι → P} (h : AffineIndependent k p)
    {w w₁ w₂ : ι → k} {s : Finset ι} (hw : ∑ i in s, w i = 1) (hw₁ : ∑ i in s, w₁ i = 1)
    (hw₂ : ∑ i in s, w₂ i = 1)
    (hs :
      s.affineCombination k p w ∈ line[k, s.affineCombination k p w₁, s.affineCombination k p w₂])
    {i j : ι} (hi : i ∈ s) (hj : j ∈ s) (hi0 : w₁ i = 0) (hj0 : w₁ j = 0)
    (hij : SignType.sign (w₂ i) = SignType.sign (w₂ j)) :
    SignType.sign (w i) = SignType.sign (w j) := by
  

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : LinearOrderedRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
p : ι → P
h : AffineIndependent k p
w w₁ w₂ : ι → k
s : Finset ι
hw : ∑ i in s, w i = 1
hw₁ : ∑ i in s, w₁ i = 1
hw₂ : ∑ i in s, w₂ i = 1
hs : (affineCombination k s p) w ∈ affineSpan k {(affineCombination k s p) w₁, (affineCombination k s p) w₂}
i j : ι
hi : i ∈ s
hj : j ∈ s
hi0 : w₁ i = 0
hj0 : w₁ j = 0
hij : SignType.sign (w₂ i) = SignType.sign (w₂ j)
⊢ SignType.sign (w i) = SignType.sign (w j)

Next tactic:
rw [affineCombination_mem_affineSpan_pair h hw hw₁ hw₂] at hs
/-- Given an affinely independent family of points, suppose that an affine combination lies in
the span of two points given as affine combinations, and suppose that, for two indices, the
coefficients in the first point in the span are zero and those in the second point in the span
have the same sign. Then the coefficients in the combination lying in the span have the same
sign. -/
theorem sign_eq_of_affineCombination_mem_affineSpan_pair {p : ι → P} (h : AffineIndependent k p)
    {w w₁ w₂ : ι → k} {s : Finset ι} (hw : ∑ i in s, w i = 1) (hw₁ : ∑ i in s, w₁ i = 1)
    (hw₂ : ∑ i in s, w₂ i = 1)
    (hs :
      s.affineCombination k p w ∈ line[k, s.affineCombination k p w₁, s.affineCombination k p w₂])
    {i j : ι} (hi : i ∈ s) (hj : j ∈ s) (hi0 : w₁ i = 0) (hj0 : w₁ j = 0)
    (hij : SignType.sign (w₂ i) = SignType.sign (w₂ j)) :
    SignType.sign (w i) = SignType.sign (w j) := by
  rw [affineCombination_mem_affineSpan_pair h hw hw₁ hw₂] at hs
  

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : LinearOrderedRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
p : ι → P
h : AffineIndependent k p
w w₁ w₂ : ι → k
s : Finset ι
hw : ∑ i in s, w i = 1
hw₁ : ∑ i in s, w₁ i = 1
hw₂ : ∑ i in s, w₂ i = 1
hs : ∃ r, ∀ i ∈ s, w i = r * (w₂ i - w₁ i) + w₁ i
i j : ι
hi : i ∈ s
hj : j ∈ s
hi0 : w₁ i = 0
hj0 : w₁ j = 0
hij : SignType.sign (w₂ i) = SignType.sign (w₂ j)
⊢ SignType.sign (w i) = SignType.sign (w j)

Next tactic:
rcases hs with ⟨r, hr⟩
/-- Given an affinely independent family of points, suppose that an affine combination lies in
the span of two points given as affine combinations, and suppose that, for two indices, the
coefficients in the first point in the span are zero and those in the second point in the span
have the same sign. Then the coefficients in the combination lying in the span have the same
sign. -/
theorem sign_eq_of_affineCombination_mem_affineSpan_pair {p : ι → P} (h : AffineIndependent k p)
    {w w₁ w₂ : ι → k} {s : Finset ι} (hw : ∑ i in s, w i = 1) (hw₁ : ∑ i in s, w₁ i = 1)
    (hw₂ : ∑ i in s, w₂ i = 1)
    (hs :
      s.affineCombination k p w ∈ line[k, s.affineCombination k p w₁, s.affineCombination k p w₂])
    {i j : ι} (hi : i ∈ s) (hj : j ∈ s) (hi0 : w₁ i = 0) (hj0 : w₁ j = 0)
    (hij : SignType.sign (w₂ i) = SignType.sign (w₂ j)) :
    SignType.sign (w i) = SignType.sign (w j) := by
  rw [affineCombination_mem_affineSpan_pair h hw hw₁ hw₂] at hs
  rcases hs with ⟨r, hr⟩
  

Proof state:
case intro
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : LinearOrderedRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
p : ι → P
h : AffineIndependent k p
w w₁ w₂ : ι → k
s : Finset ι
hw : ∑ i in s, w i = 1
hw₁ : ∑ i in s, w₁ i = 1
hw₂ : ∑ i in s, w₂ i = 1
i j : ι
hi : i ∈ s
hj : j ∈ s
hi0 : w₁ i = 0
hj0 : w₁ j = 0
hij : SignType.sign (w₂ i) = SignType.sign (w₂ j)
r : k
hr : ∀ i ∈ s, w i = r * (w₂ i - w₁ i) + w₁ i
⊢ SignType.sign (w i) = SignType.sign (w j)

Next tactic:
rw [hr i hi, hr j hj, hi0, hj0, add_zero, add_zero, sub_zero, sub_zero, sign_mul, sign_mul, hij]
/-- Given an affinely independent family of points, suppose that an affine combination lies in
the span of one point of that family and a combination of another two points of that family given
by `lineMap` with coefficient between 0 and 1. Then the coefficients of those two points in the
combination lying in the span have the same sign. -/
theorem sign_eq_of_affineCombination_mem_affineSpan_single_lineMap {p : ι → P}
    (h : AffineIndependent k p) {w : ι → k} {s : Finset ι} (hw : ∑ i in s, w i = 1) {i₁ i₂ i₃ : ι}
    (h₁ : i₁ ∈ s) (h₂ : i₂ ∈ s) (h₃ : i₃ ∈ s) (h₁₂ : i₁ ≠ i₂) (h₁₃ : i₁ ≠ i₃) (h₂₃ : i₂ ≠ i₃)
    {c : k} (hc0 : 0 < c) (hc1 : c < 1)
    (hs : s.affineCombination k p w ∈ line[k, p i₁, AffineMap.lineMap (p i₂) (p i₃) c]) :
    SignType.sign (w i₂) = SignType.sign (w i₃) := by
  

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : LinearOrderedRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
p : ι → P
h : AffineIndependent k p
w : ι → k
s : Finset ι
hw : ∑ i in s, w i = 1
i₁ i₂ i₃ : ι
h₁ : i₁ ∈ s
h₂ : i₂ ∈ s
h₃ : i₃ ∈ s
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
c : k
hc0 : 0 < c
hc1 : c < 1
hs : (affineCombination k s p) w ∈ affineSpan k {p i₁, (AffineMap.lineMap (p i₂) (p i₃)) c}
⊢ SignType.sign (w i₂) = SignType.sign (w i₃)

Next tactic:
classical
    rw [← s.affineCombination_affineCombinationSingleWeights k p h₁, ←
      s.affineCombination_affineCombinationLineMapWeights p h₂ h₃ c] at hs
    refine'
      sign_eq_of_affineCombination_mem_affineSpan_pair h hw
        (s.sum_affineCombinationSingleWeights k h₁)
        (s.sum_affineCombinationLineMapWeights h₂ h₃ c) hs h₂ h₃
        (Finset.affineCombinationSingleWeights_apply_of_ne k h₁₂.symm)
        (Finset.affineCombinationSingleWeights_apply_of_ne k h₁₃.symm) _
    rw [Finset.affineCombinationLineMapWeights_apply_left h₂₃,
      Finset.affineCombinationLineMapWeights_apply_right h₂₃]
    simp_all only [sub_pos, sign_pos]
/-- Given an affinely independent family of points, suppose that an affine combination lies in
the span of one point of that family and a combination of another two points of that family given
by `lineMap` with coefficient between 0 and 1. Then the coefficients of those two points in the
combination lying in the span have the same sign. -/
theorem sign_eq_of_affineCombination_mem_affineSpan_single_lineMap {p : ι → P}
    (h : AffineIndependent k p) {w : ι → k} {s : Finset ι} (hw : ∑ i in s, w i = 1) {i₁ i₂ i₃ : ι}
    (h₁ : i₁ ∈ s) (h₂ : i₂ ∈ s) (h₃ : i₃ ∈ s) (h₁₂ : i₁ ≠ i₂) (h₁₃ : i₁ ≠ i₃) (h₂₃ : i₂ ≠ i₃)
    {c : k} (hc0 : 0 < c) (hc1 : c < 1)
    (hs : s.affineCombination k p w ∈ line[k, p i₁, AffineMap.lineMap (p i₂) (p i₃) c]) :
    SignType.sign (w i₂) = SignType.sign (w i₃) := by
  classical
    

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : LinearOrderedRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
p : ι → P
h : AffineIndependent k p
w : ι → k
s : Finset ι
hw : ∑ i in s, w i = 1
i₁ i₂ i₃ : ι
h₁ : i₁ ∈ s
h₂ : i₂ ∈ s
h₃ : i₃ ∈ s
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
c : k
hc0 : 0 < c
hc1 : c < 1
hs : (affineCombination k s p) w ∈ affineSpan k {p i₁, (AffineMap.lineMap (p i₂) (p i₃)) c}
⊢ SignType.sign (w i₂) = SignType.sign (w i₃)

Next tactic:
rw [← s.affineCombination_affineCombinationSingleWeights k p h₁, ←
      s.affineCombination_affineCombinationLineMapWeights p h₂ h₃ c] at hs
/-- Given an affinely independent family of points, suppose that an affine combination lies in
the span of one point of that family and a combination of another two points of that family given
by `lineMap` with coefficient between 0 and 1. Then the coefficients of those two points in the
combination lying in the span have the same sign. -/
theorem sign_eq_of_affineCombination_mem_affineSpan_single_lineMap {p : ι → P}
    (h : AffineIndependent k p) {w : ι → k} {s : Finset ι} (hw : ∑ i in s, w i = 1) {i₁ i₂ i₃ : ι}
    (h₁ : i₁ ∈ s) (h₂ : i₂ ∈ s) (h₃ : i₃ ∈ s) (h₁₂ : i₁ ≠ i₂) (h₁₃ : i₁ ≠ i₃) (h₂₃ : i₂ ≠ i₃)
    {c : k} (hc0 : 0 < c) (hc1 : c < 1)
    (hs : s.affineCombination k p w ∈ line[k, p i₁, AffineMap.lineMap (p i₂) (p i₃) c]) :
    SignType.sign (w i₂) = SignType.sign (w i₃) := by
  classical
    rw [← s.affineCombination_affineCombinationSingleWeights k p h₁, ←
      s.affineCombination_affineCombinationLineMapWeights p h₂ h₃ c] at hs
    

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : LinearOrderedRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
p : ι → P
h : AffineIndependent k p
w : ι → k
s : Finset ι
hw : ∑ i in s, w i = 1
i₁ i₂ i₃ : ι
h₁ : i₁ ∈ s
h₂ : i₂ ∈ s
h₃ : i₃ ∈ s
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
c : k
hc0 : 0 < c
hc1 : c < 1
hs :
  (affineCombination k s p) w ∈
    affineSpan k
      {(affineCombination k s p) (affineCombinationSingleWeights k i₁),
        (affineCombination k s p) (affineCombinationLineMapWeights i₂ i₃ c)}
⊢ SignType.sign (w i₂) = SignType.sign (w i₃)

Next tactic:
refine'
      sign_eq_of_affineCombination_mem_affineSpan_pair h hw
        (s.sum_affineCombinationSingleWeights k h₁)
        (s.sum_affineCombinationLineMapWeights h₂ h₃ c) hs h₂ h₃
        (Finset.affineCombinationSingleWeights_apply_of_ne k h₁₂.symm)
        (Finset.affineCombinationSingleWeights_apply_of_ne k h₁₃.symm) _
/-- Given an affinely independent family of points, suppose that an affine combination lies in
the span of one point of that family and a combination of another two points of that family given
by `lineMap` with coefficient between 0 and 1. Then the coefficients of those two points in the
combination lying in the span have the same sign. -/
theorem sign_eq_of_affineCombination_mem_affineSpan_single_lineMap {p : ι → P}
    (h : AffineIndependent k p) {w : ι → k} {s : Finset ι} (hw : ∑ i in s, w i = 1) {i₁ i₂ i₃ : ι}
    (h₁ : i₁ ∈ s) (h₂ : i₂ ∈ s) (h₃ : i₃ ∈ s) (h₁₂ : i₁ ≠ i₂) (h₁₃ : i₁ ≠ i₃) (h₂₃ : i₂ ≠ i₃)
    {c : k} (hc0 : 0 < c) (hc1 : c < 1)
    (hs : s.affineCombination k p w ∈ line[k, p i₁, AffineMap.lineMap (p i₂) (p i₃) c]) :
    SignType.sign (w i₂) = SignType.sign (w i₃) := by
  classical
    rw [← s.affineCombination_affineCombinationSingleWeights k p h₁, ←
      s.affineCombination_affineCombinationLineMapWeights p h₂ h₃ c] at hs
    refine'
      sign_eq_of_affineCombination_mem_affineSpan_pair h hw
        (s.sum_affineCombinationSingleWeights k h₁)
        (s.sum_affineCombinationLineMapWeights h₂ h₃ c) hs h₂ h₃
        (Finset.affineCombinationSingleWeights_apply_of_ne k h₁₂.symm)
        (Finset.affineCombinationSingleWeights_apply_of_ne k h₁₃.symm) _
    

Proof state:
k : Type u_1
V : Type u_2
P : Type u_3
inst✝³ : LinearOrderedRing k
inst✝² : AddCommGroup V
inst✝¹ : Module k V
inst✝ : AffineSpace V P
ι : Type u_4
p : ι → P
h : AffineIndependent k p
w : ι → k
s : Finset ι
hw : ∑ i in s, w i = 1
i₁ i₂ i₃ : ι
h₁ : i₁ ∈ s
h₂ : i₂ ∈ s
h₃ : i₃ ∈ s
h₁₂ : i₁ ≠ i₂
h₁₃ : i₁ ≠ i₃
h₂₃ : i₂ ≠ i₃
c : k
hc0 : 0 < c
hc1 : c < 1
hs :
  (affineCombination k s p) w ∈
    affineSpan k
      {(affineCombination k s p) (affineCombinationSingleWeights k i₁),
        (affineCombination k s p) (affineCombinationLineMapWeights i₂ i₃ c)}
⊢ SignType.sign (affineCombinationLineMapWeights i₂ i₃ c i₂) =
    SignType.sign (affineCombinationLineMapWeights i₂ i₃ c i₃)

Next tactic:
rw [Finset.affineCombinationLineMapWeights_apply_left h₂₃,
      Finset.affineCombinationLineMapWeights_apply_right h₂₃]