lean_workbook_plus_75033

Proved

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

Let $x,y\ge 0 ,4y-x\le 12,y+4x\le 20$ Prove that : \n

9-x^2-y^2+xy+2(x+y)\le 13

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_75033 (x y : ℝ) (hx : 0 ≤ x) (hy : 0 ≤ y) (h1 : 4 * y - x ≤ 12) (h2 : y + 4 * x ≤ 20) : 9 - x ^ 2 - y ^ 2 + x * y + 2 * (x + y) ≤ 13   :=  by sorry

Source

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

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