lean_workbook_plus_69076

Proved

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

Let $a$ and $b$ be positive integers. Prove that there exist positive integers $x$ and $y$ such that: $\binom{x+y}{2} = ax + by$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_69076 (a b : ℕ) (hab : 0 < a ∧ 0 < b) : ∃ x y : ℕ, (Nat.choose (x+y) 2 = a*x + b*y)   :=  by sorry

Source