l3lab/ntp-mathlib huggingface dataset:
theorem CHSH_id [CommRing R] {A₀ A₁ B₀ B₁ : R} (A₀_inv : A₀ ^ 2 = 1) (A₁_inv : A₁ ^ 2 = 1)
    (B₀_inv : B₀ ^ 2 = 1) (B₁_inv : B₁ ^ 2 = 1) :
    (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) * (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) =
      4 * (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) := by
  -- If we had a Gröbner basis algorithm, this would be trivial.
  -- Without one, it is somewhat tedious!
  rw [← sub_eq_zero]
  ring_nf
  

Proof state:
R : Type u
inst✝ : CommRing R
A₀ A₁ B₀ B₁ : R
A₀_inv : A₀ ^ 2 = 1
A₁_inv : A₁ ^ 2 = 1
B₀_inv : B₀ ^ 2 = 1
B₁_inv : B₁ ^ 2 = 1
⊢ -4 + (A₀ * B₀ ^ 2 * A₁ * 2 - A₀ * B₁ ^ 2 * A₁ * 2) + A₀ ^ 2 * B₀ * B₁ * 2 + A₀ ^ 2 * B₀ ^ 2 +
          (A₀ ^ 2 * B₁ ^ 2 - B₀ * B₁ * A₁ ^ 2 * 2) +
        B₀ ^ 2 * A₁ ^ 2 +
      B₁ ^ 2 * A₁ ^ 2 =
    0

Next tactic:
simp_all
theorem CHSH_id [CommRing R] {A₀ A₁ B₀ B₁ : R} (A₀_inv : A₀ ^ 2 = 1) (A₁_inv : A₁ ^ 2 = 1)
    (B₀_inv : B₀ ^ 2 = 1) (B₁_inv : B₁ ^ 2 = 1) :
    (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) * (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) =
      4 * (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) := by
  -- If we had a Gröbner basis algorithm, this would be trivial.
  -- Without one, it is somewhat tedious!
  rw [← sub_eq_zero]
  ring_nf
  simp_all
  

Proof state:
R : Type u
inst✝ : CommRing R
A₀ A₁ B₀ B₁ : R
A₀_inv : A₀ ^ 2 = 1
A₁_inv : A₁ ^ 2 = 1
B₀_inv : B₀ ^ 2 = 1
B₁_inv : B₁ ^ 2 = 1
⊢ -4 + B₀ * B₁ * 2 + 1 + (1 - B₀ * B₁ * 2) + 1 + 1 = 0

Next tactic:
ring_nf
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
⊢ A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2

Next tactic:
let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
⊢ A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2

Next tactic:
have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    conv_rhs =>
      arg 2
      arg 1
      rw [← sa]
    convert smul_le_smul_of_nonneg (R := ℝ) (star_mul_self_nonneg P) _
    · simp
    · norm_num
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
⊢ 0 ≤ P

Next tactic:
have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
⊢ 0 ≤ P

Next tactic:
have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
⊢ P = (1 / 4) • (P * P)

Next tactic:
have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by 

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
⊢ 4 * P = 4 • P

Next tactic:
simp [Algebra.smul_def]
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
h : 4 * P = 4 • P
⊢ P = (1 / 4) • (P * P)

Next tactic:
rw [idem, h, ← mul_smul]
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
h : 4 * P = 4 • P
⊢ P = (1 / 4 * 4) • P

Next tactic:
norm_num
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
⊢ 0 ≤ P

Next tactic:
have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
⊢ star P = P

Next tactic:
dsimp
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
⊢ star (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) = 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁

Next tactic:
simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
⊢ 0 ≤ P

Next tactic:
rw [idem']
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
⊢ 0 ≤ (1 / 4) • (P * P)

Next tactic:
conv_rhs =>
      arg 2
      arg 1
      rw [← sa]
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    conv_rhs =>
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
| (1 / 4) • (P * P)

Next tactic:
arg 2
      arg 1
      rw [← sa]
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    conv_rhs =>
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
| (1 / 4) • (P * P)

Next tactic:
arg 2
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    conv_rhs =>
      arg 2
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
| P * P

Next tactic:
arg 1
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    conv_rhs =>
      arg 2
      arg 1
      

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
| P

Next tactic:
rw [← sa]
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    conv_rhs =>
      arg 2
      arg 1
      rw [← sa]
    

Proof state:
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
⊢ 0 ≤ (1 / 4) • (star P * P)

Next tactic:
convert smul_le_smul_of_nonneg (R := ℝ) (star_mul_self_nonneg P) _
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    conv_rhs =>
      arg 2
      arg 1
      rw [← sa]
    convert smul_le_smul_of_nonneg (R := ℝ) (star_mul_self_nonneg P) _
    · 

Proof state:
case h.e'_3
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
⊢ 0 = (1 / 4) • 0

Next tactic:
simp
/-- Given a CHSH tuple (A₀, A₁, B₀, B₁) in a *commutative* ordered `*`-algebra over ℝ,
`A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2`.

(We could work over ℤ[⅟2] if we wanted to!)
-/
theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarOrderedRing R] [Algebra ℝ R]
    [OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
    A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by
  let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
  have i₁ : 0 ≤ P := by
    have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
    have idem' : P = (1 / 4 : ℝ) • (P * P) := by
      have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
      rw [idem, h, ← mul_smul]
      norm_num
    have sa : star P = P := by
      dsimp
      simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
        T.B₁_sa, mul_comm B₀, mul_comm B₁]
    rw [idem']
    conv_rhs =>
      arg 2
      arg 1
      rw [← sa]
    convert smul_le_smul_of_nonneg (R := ℝ) (star_mul_self_nonneg P) _
    · simp
    · 

Proof state:
case convert_2
R : Type u
inst✝³ : OrderedCommRing R
inst✝² : StarOrderedRing R
inst✝¹ : Algebra ℝ R
inst✝ : OrderedSMul ℝ R
A₀ A₁ B₀ B₁ : R
T : IsCHSHTuple A₀ A₁ B₀ B₁
P : R := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
idem : P * P = 4 * P
idem' : P = (1 / 4) • (P * P)
sa : star P = P
⊢ 0 ≤ 1 / 4

Next tactic:
norm_num