lean_workbook_plus_66130
ProvedLet be reals. Prove that
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_66130 : ∀ a b : ℝ, a^2 + a * b + b^2 ≥ 3 * (a + b - 1) ∧ a^2 + a * b + b^2 ≥ 3 * a * b * (a + b - a * b) ∧ a^2 + a * b + b^2 ≤ 3 * (a^2 - a + 1) * (b^2 - b + 1) := by sorry
Source