lean_workbook_plus_42693

Proved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

If $a,b,c,d\ge 1$ \n\n It is sufficient to prove $8+abc+bcd+cda+dab\ge 3(a+b+c+d)$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_42693 (a b c d : ℝ) (ha : 1 ≤ a) (hb : 1 ≤ b) (hc : 1 ≤ c) (hd : 1 ≤ d) : 8 + a * b * c + b * c * d + c * d * a + d * a * b ≥ 3 * (a + b + c + d)   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook

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