lean_workbook_plus_9378

Proved

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

Prove that if $x^4+y^4<4$ and $x^3+y^3>3$ , then $x^2+y^2>2$ .

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_9378 (x y : ℝ) (h1 : x ^ 4 + y ^ 4 < 4) (h2 : x ^ 3 + y ^ 3 > 3) : x ^ 2 + y ^ 2 > 2   :=  by sorry

Source