theorem extracted_formal_statement_142.{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] (r_Φ : ℝ)
  (hΦ : range Φ ⊆ ball 0 r_Φ)
  (h1 :
    ∀ (k : ℕ+),
      (1 ⊓ (1 + 1 / ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F)) * ADMM.ρ E₁ E₂ F *
          ‖(OptProblem.A₁ E₂) (e₁ (↑k + 1)) + (OptProblem.A₂ E₁) (e₂ (↑k + 1))‖ ^ 2 ≤
        (ADMM.τ E₁ E₂ F ⊓ (1 + ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F ^ 2)) * ADMM.ρ E₁ E₂ F *
            ‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑k - ADMM.x₂ E₁ F (↑k + 1))‖ ^ 2 +
          (1 ⊓ (1 + 1 / ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F)) * ADMM.ρ E₁ E₂ F *
            ‖(OptProblem.A₁ E₂) (e₁ (↑k + 1)) + (OptProblem.A₂ E₁) (e₂ (↑k + 1))‖ ^ 2)
  (h2 :
    ∀ (k : ℕ+),
      (ADMM.τ E₁ E₂ F ⊓ (1 + ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F ^ 2)) * ADMM.ρ E₁ E₂ F *
            ‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑k - ADMM.x₂ E₁ F (↑k + 1))‖ ^ 2 +
          (1 ⊓ (1 + 1 / ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F)) * ADMM.ρ E₁ E₂ F *
            ‖(OptProblem.A₁ E₂) (e₁ (↑k + 1)) + (OptProblem.A₂ E₁) (e₂ (↑k + 1))‖ ^ 2 ≤
        Φ ↑k - Φ (↑k + 1))
  (k : ℕ+) (h3a : ‖Φ ↑k‖ < r_Φ) (h3b : ‖Φ (↑k + 1)‖ < r_Φ) : ‖Φ ↑k‖ + ‖Φ (↑k + 1)‖ < r_Φ + r_Φ := 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
r_Φ : ℝ
hΦ : range Φ ⊆ ball 0 r_Φ
h1 :
  ∀ (k : ℕ+),
    (1 ⊓ (1 + 1 / ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F)) * ADMM.ρ E₁ E₂ F *
        ‖(OptProblem.A₁ E₂) (e₁ (↑k + 1)) + (OptProblem.A₂ E₁) (e₂ (↑k + 1))‖ ^ 2 ≤
      (ADMM.τ E₁ E₂ F ⊓ (1 + ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F ^ 2)) * ADMM.ρ E₁ E₂ F *
          ‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑k - ADMM.x₂ E₁ F (↑k + 1))‖ ^ 2 +
        (1 ⊓ (1 + 1 / ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F)) * ADMM.ρ E₁ E₂ F *
          ‖(OptProblem.A₁ E₂) (e₁ (↑k + 1)) + (OptProblem.A₂ E₁) (e₂ (↑k + 1))‖ ^ 2
h2 :
  ∀ (k : ℕ+),
    (ADMM.τ E₁ E₂ F ⊓ (1 + ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F ^ 2)) * ADMM.ρ E₁ E₂ F *
          ‖(OptProblem.A₂ E₁) (ADMM.x₂ E₁ F ↑k - ADMM.x₂ E₁ F (↑k + 1))‖ ^ 2 +
        (1 ⊓ (1 + 1 / ADMM.τ E₁ E₂ F - ADMM.τ E₁ E₂ F)) * ADMM.ρ E₁ E₂ F *
          ‖(OptProblem.A₁ E₂) (e₁ (↑k + 1)) + (OptProblem.A₂ E₁) (e₂ (↑k + 1))‖ ^ 2 ≤
      Φ ↑k - Φ (↑k + 1)
k : ℕ+
h3a : ‖Φ ↑k‖ < r_Φ
h3b : ‖Φ (↑k + 1)‖ < r_Φ
⊢ ‖Φ ↑k‖ + ‖Φ (↑k + 1)‖ < r_Φ + r_Φ

Tactic: apply add_lt_add h3a h3b

State after:

Relevant lemmas:
add_lt_add : ∀ {α : Type u_1} [inst : Add α] [inst_10 : Preorder α] [inst_11 : AddLeftStrictMono α]
  [inst_12 : AddRightStrictMono α] {a b c d : α}, a < b → c < d → a + c < b + d