Nonnegativity of a shifted cube

Proved

WorkbookSource.problem_33759

by wamlart · Sep 12, 2026 · Mathlib 0df444a (Lean v4.33.1)

lean-workbooksource-checked

Let $a$ be real with $a>-1$ . Then

(a+1)^3\ge0.

Source: InternLM Lean-Workbook, record lean_workbook_33759 (Apache-2.0). The complete source proposition and explicit variable declarations are preserved.

Preamble

import Mathlib
open Real Nat

Formal statement

theorem WorkbookSource.problem_33759 (a : ℝ) (h : a > -1) : (a + 1)^3 ≥ 0  :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, record lean_workbook_33759; Apache-2.0

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