by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)
The following inequality is equivalent to \n\n 3R2−2(s2−4Rr−r2)s4−8Rrs2+2r2s2+16R2r2+8Rr3+r4≥0 \n\n ⟺−s4+(6R2+8Rr−2r2)s2−24R3r−22R2r2−r4−8Rr3≥0 \n\n ⟺−s4+(4R2+20Rr−2r2)s2−r(4R+r)3+2R((R−6r)s2+r(4R+r)(2r+5R))≥0 \n\n can prove −s4+(4R2+20Rr−2r2)s2−r(4R+r)3≥0 \n\n and \n\n (R−6r)s2+r(4R+r)(2r+5R)≥−4rs2+r(4R+r)(2r+5R) \n\n =r(−4s2+(4R+r)(2r+5R))≥r(−4(4R2+4Rr+3r2)+(4R+r)(2r+5R)) \n\n =r(5r+4R)(R−2r)≥0
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_53634 :
∀ (R r s : ℝ), 3 * R^2 - (s^4 - 8 * R * r * s^2 + 2 * r^2 * s^2 + 16 * R^2 * r^2 + 8 * R * r^3 + r^4) / (2 * (s^2 - 4 * R * r - r^2)) ≥ 0 := by sorry