theorem extracted_formal_statement_51.{u_3, u_2, u_1} {E₁ : Type u_1} {E₂ : Type u_2} {F : Type u_3}
  [inst : NormedAddCommGroup E₁] [inst_1 : InnerProductSpace ℝ E₁] [inst_2 : FiniteDimensional ℝ E₁]
  [inst_3 : NormedAddCommGroup E₂] [inst_4 : InnerProductSpace ℝ E₂] [inst_5 : FiniteDimensional ℝ E₂]
  [inst_6 : NormedAddCommGroup F] [inst_7 : InnerProductSpace ℝ F] [inst_8 : FiniteDimensional ℝ F]
  {admm : ADMM E₁ E₂ F} {admm_kkt : Existance_of_kkt admm} [inst_9 : Setting E₁ E₂ F admm admm_kkt] (n : ℕ+)
  (htau : 0 < ADMM.τ E₁ E₂ F ∧ ADMM.τ E₁ E₂ F ≤ 1)
  (this_1 :
    (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F * ‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
        (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
          ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2 =
      (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
        (‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
          ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2))
  (this :
    2 * M (n + 1) =
      (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
        (2 *
          ⟪(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F (↑n + 1) - ADMM.x₂ E₁ F ↑n),
            (OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂⟫_ℝ))
  (h_original_goal :
    (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
        (2 *
          ⟪(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F (↑n + 1) - ADMM.x₂ E₁ F ↑n),
            (OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂⟫_ℝ) ≤
      (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
        (‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
          ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2)) :
  0 ≤ 1 - ADMM.τ E₁ E₂ F := sorry

State before:
E₁ : Type u_1
E₂ : Type u_2
F : Type u_3
inst✝⁹ : NormedAddCommGroup E₁
inst✝⁸ : InnerProductSpace ℝ E₁
inst✝⁷ : FiniteDimensional ℝ E₁
inst✝⁶ : NormedAddCommGroup E₂
inst✝⁵ : InnerProductSpace ℝ E₂
inst✝⁴ : FiniteDimensional ℝ E₂
inst✝³ : NormedAddCommGroup F
inst✝² : InnerProductSpace ℝ F
inst✝¹ : FiniteDimensional ℝ F
admm : ADMM E₁ E₂ F
admm_kkt : Existance_of_kkt admm
inst✝ : Setting E₁ E₂ F admm admm_kkt
n : ℕ+
htau : 0 < ADMM.τ E₁ E₂ F ∧ ADMM.τ E₁ E₂ F ≤ 1
this✝ :
  (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F * ‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
      (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
        ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2 =
    (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
      (‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
        ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2)
this :
  2 * M (n + 1) =
    (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
      (2 *
        ⟪(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F (↑n + 1) - ADMM.x₂ E₁ F ↑n),
          (OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂⟫_ℝ)
⊢ (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
      (2 *
        ⟪(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F (↑n + 1) - ADMM.x₂ E₁ F ↑n),
          (OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂⟫_ℝ) ≤
    (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
      (‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
        ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2)

Tactic: apply mul_le_mul_of_nonneg_left (basic_inequ₁' n)
    have : 0 ≤ 1 - τ := by linarith [htau.1]
    apply mul_nonneg

State after:
[case ha
 E₁ : Type u_1
 E₂ : Type u_2
 F : Type u_3
 inst✝⁹ : NormedAddCommGroup E₁
 inst✝⁸ : InnerProductSpace ℝ E₁
 inst✝⁷ : FiniteDimensional ℝ E₁
 inst✝⁶ : NormedAddCommGroup E₂
 inst✝⁵ : InnerProductSpace ℝ E₂
 inst✝⁴ : FiniteDimensional ℝ E₂
 inst✝³ : NormedAddCommGroup F
 inst✝² : InnerProductSpace ℝ F
 inst✝¹ : FiniteDimensional ℝ F
 admm : ADMM E₁ E₂ F
 admm_kkt : Existance_of_kkt admm
 inst✝ : Setting E₁ E₂ F admm admm_kkt
 n : ℕ+
 htau : 0 < ADMM.τ E₁ E₂ F ∧ ADMM.τ E₁ E₂ F ≤ 1
 this✝¹ :
   (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F * ‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
       (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
         ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2 =
     (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
       (‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
         ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2)
 this✝ :
   2 * M (n + 1) =
     (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
       (2 *
         ⟪(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F (↑n + 1) - ADMM.x₂ E₁ F ↑n),
           (OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂⟫_ℝ)
 this : 0 ≤ 1 - ADMM.τ E₁ E₂ F
 ⊢ 0 ≤ 1 - ADMM.τ E₁ E₂ F,
 case hb
 E₁ : Type u_1
 E₂ : Type u_2
 F : Type u_3
 inst✝⁹ : NormedAddCommGroup E₁
 inst✝⁸ : InnerProductSpace ℝ E₁
 inst✝⁷ : FiniteDimensional ℝ E₁
 inst✝⁶ : NormedAddCommGroup E₂
 inst✝⁵ : InnerProductSpace ℝ E₂
 inst✝⁴ : FiniteDimensional ℝ E₂
 inst✝³ : NormedAddCommGroup F
 inst✝² : InnerProductSpace ℝ F
 inst✝¹ : FiniteDimensional ℝ F
 admm : ADMM E₁ E₂ F
 admm_kkt : Existance_of_kkt admm
 inst✝ : Setting E₁ E₂ F admm admm_kkt
 n : ℕ+
 htau : 0 < ADMM.τ E₁ E₂ F ∧ ADMM.τ E₁ E₂ F ≤ 1
 this✝¹ :
   (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F * ‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
       (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
         ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2 =
     (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
       (‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n - ADMM.x₂ E₁ F (↑n + 1))‖ ^ 2 +
         ‖(OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂‖ ^ 2)
 this✝ :
   2 * M (n + 1) =
     (1 - ADMM.τ E₁ E₂ F) * ADMM.ρ E₁ E₂ F *
       (2 *
         ⟪(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F (↑n + 1) - ADMM.x₂ E₁ F ↑n),
           (OptProblem.A₁ E₂) (ADMM.x₁ E₂ F ↑n) + (OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑n) - OptProblem.b E₁ E₂⟫_ℝ)
 this : 0 ≤ 1 - ADMM.τ E₁ E₂ F
 ⊢ 0 ≤ ADMM.ρ E₁ E₂ F]

Relevant lemmas:
mul_nonneg : ∀ {α : Type u_3} {a b : α} [inst : MulZeroClass α] [inst_10 : Preorder α] [inst_11 : PosMulMono α],
  0 ≤ a → 0 ≤ b → 0 ≤ a * b
mul_le_mul_of_nonneg_left : ∀ {α : Type u_3} {a b c : α} [inst : Mul α] [inst_10 : Zero α] [inst_11 : Preorder α]
  [inst_12 : PosMulMono α], b ≤ c → 0 ≤ a → a * b ≤ a * c