theorem extracted_formal_statement_77 : 0 < 2 ^ 2 := sorry

State before:
E : Type u_1
inst✝² : NormedAddCommGroup E
inst✝¹ : InnerProductSpace ℝ E
inst✝ : CompleteSpace E
f : E → ℝ
f' : E → E
xm x₀ : E
γ : ℕ+ → ℝ
alg : Nesterov f f' γ x₀
hfun : ConvexOn ℝ univ f
hg : ∀ (k : ℕ+), γ k = 2 / (↑↑k + 1)
min : IsMinOn f univ xm
con : ∀ (k : ℕ+), (1 - γ k) / γ k ^ 2 ≤ 1 / γ (k - 1) ^ 2
h4 :
  ∀ (k : ℕ+),
    f (Nesterov.x f f' γ x₀ ↑k) - f xm - (1 - γ k) * (f (Nesterov.x f f' γ x₀ (↑k - 1)) - f xm) ≤
      ↑(Nesterov.l f f' γ x₀) * γ k ^ 2 / 2 *
        (‖Nesterov.v f f' γ x₀ (↑k - 1) - xm‖ ^ 2 - ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2)
h5 :
  ∀ (k : ℕ+),
    1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
        ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
      1 / γ (k - 1) ^ 2 * (f (Nesterov.x f f' γ x₀ (↑k - 1)) - f xm) +
        ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ (↑k - 1) - xm‖ ^ 2
h6 :
  ∀ (k : ℕ+),
    1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
        ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
      1 / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 1) - f xm) +
        ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 1 - xm‖ ^ 2
h7 :
  1 / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 1) - f xm) + ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 1 - xm‖ ^ 2 ≤
    (1 - γ 1) / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 0) - f xm) +
      ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 0 - xm‖ ^ 2
k : ℕ+
h8 :
  1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
      ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
    ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2
h9 : 1 / (2 / (↑↑k + 1)) ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) ≤ ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2
h10 :
  ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2 / (1 / (2 / (↑↑k + 1)) ^ 2) =
    2 * ↑(Nesterov.l f f' γ x₀) / (↑↑k + 1) ^ 2 * ‖x₀ - xm‖ ^ 2
⊢ 0 < (↑↑k + 1) ^ 2 / 2 ^ 2

Tactic: apply div_pos

State after:
[case ha
 E : Type u_1
 inst✝² : NormedAddCommGroup E
 inst✝¹ : InnerProductSpace ℝ E
 inst✝ : CompleteSpace E
 f : E → ℝ
 f' : E → E
 xm x₀ : E
 γ : ℕ+ → ℝ
 alg : Nesterov f f' γ x₀
 hfun : ConvexOn ℝ univ f
 hg : ∀ (k : ℕ+), γ k = 2 / (↑↑k + 1)
 min : IsMinOn f univ xm
 con : ∀ (k : ℕ+), (1 - γ k) / γ k ^ 2 ≤ 1 / γ (k - 1) ^ 2
 h4 :
   ∀ (k : ℕ+),
     f (Nesterov.x f f' γ x₀ ↑k) - f xm - (1 - γ k) * (f (Nesterov.x f f' γ x₀ (↑k - 1)) - f xm) ≤
       ↑(Nesterov.l f f' γ x₀) * γ k ^ 2 / 2 *
         (‖Nesterov.v f f' γ x₀ (↑k - 1) - xm‖ ^ 2 - ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2)
 h5 :
   ∀ (k : ℕ+),
     1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
         ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
       1 / γ (k - 1) ^ 2 * (f (Nesterov.x f f' γ x₀ (↑k - 1)) - f xm) +
         ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ (↑k - 1) - xm‖ ^ 2
 h6 :
   ∀ (k : ℕ+),
     1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
         ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
       1 / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 1) - f xm) +
         ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 1 - xm‖ ^ 2
 h7 :
   1 / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 1) - f xm) + ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 1 - xm‖ ^ 2 ≤
     (1 - γ 1) / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 0) - f xm) +
       ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 0 - xm‖ ^ 2
 k : ℕ+
 h8 :
   1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
       ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
     ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2
 h9 : 1 / (2 / (↑↑k + 1)) ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) ≤ ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2
 h10 :
   ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2 / (1 / (2 / (↑↑k + 1)) ^ 2) =
     2 * ↑(Nesterov.l f f' γ x₀) / (↑↑k + 1) ^ 2 * ‖x₀ - xm‖ ^ 2
 ⊢ 0 < (↑↑k + 1) ^ 2,
 case hb
 E : Type u_1
 inst✝² : NormedAddCommGroup E
 inst✝¹ : InnerProductSpace ℝ E
 inst✝ : CompleteSpace E
 f : E → ℝ
 f' : E → E
 xm x₀ : E
 γ : ℕ+ → ℝ
 alg : Nesterov f f' γ x₀
 hfun : ConvexOn ℝ univ f
 hg : ∀ (k : ℕ+), γ k = 2 / (↑↑k + 1)
 min : IsMinOn f univ xm
 con : ∀ (k : ℕ+), (1 - γ k) / γ k ^ 2 ≤ 1 / γ (k - 1) ^ 2
 h4 :
   ∀ (k : ℕ+),
     f (Nesterov.x f f' γ x₀ ↑k) - f xm - (1 - γ k) * (f (Nesterov.x f f' γ x₀ (↑k - 1)) - f xm) ≤
       ↑(Nesterov.l f f' γ x₀) * γ k ^ 2 / 2 *
         (‖Nesterov.v f f' γ x₀ (↑k - 1) - xm‖ ^ 2 - ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2)
 h5 :
   ∀ (k : ℕ+),
     1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
         ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
       1 / γ (k - 1) ^ 2 * (f (Nesterov.x f f' γ x₀ (↑k - 1)) - f xm) +
         ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ (↑k - 1) - xm‖ ^ 2
 h6 :
   ∀ (k : ℕ+),
     1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
         ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
       1 / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 1) - f xm) +
         ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 1 - xm‖ ^ 2
 h7 :
   1 / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 1) - f xm) + ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 1 - xm‖ ^ 2 ≤
     (1 - γ 1) / γ 1 ^ 2 * (f (Nesterov.x f f' γ x₀ 0) - f xm) +
       ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ 0 - xm‖ ^ 2
 k : ℕ+
 h8 :
   1 / γ k ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) +
       ↑(Nesterov.l f f' γ x₀) / 2 * ‖Nesterov.v f f' γ x₀ ↑k - xm‖ ^ 2 ≤
     ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2
 h9 : 1 / (2 / (↑↑k + 1)) ^ 2 * (f (Nesterov.x f f' γ x₀ ↑k) - f xm) ≤ ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2
 h10 :
   ↑(Nesterov.l f f' γ x₀) / 2 * ‖x₀ - xm‖ ^ 2 / (1 / (2 / (↑↑k + 1)) ^ 2) =
     2 * ↑(Nesterov.l f f' γ x₀) / (↑↑k + 1) ^ 2 * ‖x₀ - xm‖ ^ 2
 ⊢ 0 < 2 ^ 2]

Relevant lemmas:
div_pos : ∀ {G₀ : Type u_2} [inst : GroupWithZero G₀] [inst_1 : PartialOrder G₀] [inst_2 : ZeroLEOneClass G₀]
  [inst_3 : PosMulReflectLT G₀] {a b : G₀} [inst_4 : PosMulStrictMono G₀], 0 < a → 0 < b → 0 < a / b