by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)
Let a1,a2,⋯,an∈[0,1](n≥2). Prove that
i=1∑nj=i∏ajn(1−ai)≤1.
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_2833 (n : ℕ) (a : Fin n → ℝ) (ha : ∀ i, a i ∈ Set.Icc 0 1) :
∑ i, (∏ j, if j ≠ i then Real.sqrt (a j ^ n) * Real.sqrt (1 - a i) else 0) ≤ 1 := by sorry