Lean-Workbook Plus 11509: Logarithmic inequality

Proved

WorkbookRestored.plus_11509

by wamlart · Sep 12, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

lean-workbookrestored-importssource-checked

Prove for every $x>0$ : $ln(x^3-2x^2+x+1)\geq 0$

Source: Lean-Workbook row lean_workbook_plus_11509 (Apache-2.0). The unchanged proposition comes from the original record; its missing mathematical imports and namespaces are restored here.

Preamble

import Mathlib.Analysis.SpecialFunctions.Log.Basic
open Real

Formal statement

theorem WorkbookRestored.plus_11509 (x : ℝ) (hx: x > 0) : Real.log (x^3 - 2 * x^2 + x + 1) ≥ 0   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, row lean_workbook_plus_11509; immutable original Prove2Me node 4dc38eb9-9cb2-40ee-80fc-407c7e8c35d7

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