by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)
Prove that x+y+z+t21+x+y+z2+t1+x+y2+z+t1+x2+y+z+t1≤4+t2−t1+4−z+z21+4−y+y21+x2+4−x1 given x,y,z,t are positive numbers such that x+y+z+t≥4.
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_70834 (x y z t : ℝ) (h : x + y + z + t ≥ 4) : 1 / (x + y + z + t ^ 2) + 1 / (x + y + z ^ 2 + t) + 1 / (x + y ^ 2 + z + t) + 1 / (x ^ 2 + y + z + t) ≤ 1 / (4 + t ^ 2 - t) + 1 / (4 - z + z ^ 2) + 1 / (4 - y + y ^ 2) + 1 / (x ^ 2 + 4 - x) := by sorry