lean_workbook_plus_3911

Proved

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

$a^3+b^3+c^3-3abc=(a+b+c)(a^2+b^2+c^2)-\sum_{cyc} (a^2b+b^2a) - 3abc$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_3911 : ∀ a b c : ℝ, a^3 + b^3 + c^3 - 3*a*b*c = (a + b + c)*(a^2 + b^2 + c^2) - (a^2*b + b^2*a + a^2*c + c^2*a + b^2*c + c^2*b) - 3*a*b*c   :=  by sorry

Source

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

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