theorem extracted_formal_statement_51.{u_1} {Ω : Type u_1} [inst : MeasurableSpace Ω] (μ : Measure Ω)
  [inst_1 : IsProbabilityMeasure μ] {n : ℕ} {X : Fin n → Ω → ℝ} (hXm : ∀ (i : Fin n), Measurable (X i))
  (hX_bdd : ∀ (i : Fin n), ∀ᵐ (ω : Ω) ∂μ, |X i ω| ≤ 1) (τ : ℝ) (i : Fin n) (h1 : Integrable (fun ω => 1 + τ * X i ω) μ)
  (h_bound : ∀ᵐ (a : Ω) ∂μ, X i a ^ 2 ≤ 1) (h_lbound : ∀ᵐ (a : Ω) ∂μ, X i a ^ 2 ≥ 0) (a : Ω) (ha : X i a ^ 2 ≤ 1)
  (hlb : X i a ^ 2 ≥ 0) : 0 ≤ X i a ^ 2 := sorry

State before:
case h.left
Ω : Type u_1
inst : MeasurableSpace Ω
μ : Measure Ω
inst_1 : IsProbabilityMeasure μ
n : ℕ
X : Fin n → Ω → ℝ
hXm : ∀ (i : Fin n), Measurable (X i)
hX_bdd : ∀ (i : Fin n), ∀ᵐ (ω : Ω) ∂μ, |X i ω| ≤ 1
τ : ℝ
i : Fin n
h1 : Integrable (fun ω => 1 + τ * X i ω) μ
h_bound : ∀ᵐ (a : Ω) ∂μ, X i a ^ 2 ≤ 1
h_lbound : ∀ᵐ (a : Ω) ∂μ, X i a ^ 2 ≥ 0
a : Ω
ha : X i a ^ 2 ≤ 1
hlb : X i a ^ 2 ≥ 0
⊢ 0 ≤ X i a ^ 2

Tactic: exact hlb

State after:

Relevant lemmas: