lean_workbook_plus_17600

Proved

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

If $x\ge 1$ , prove that $x^{4}-x^{3}+x^{2}-x+1>0$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_17600 (x : ℝ) (hx : 1 ≤ x) : x^4 - x^3 + x^2 - x + 1 > 0   :=  by sorry

Source