Prove2Me

Binomial coefficient identity #29516

Proved
WorkbookCorrected.plus_29516

by carlok · Sep 29, 2026 · Mathlib 0df444a (Lean v4.33.1)

arithmeticcorrectedelementaryworkbook

The elementary natural-number / rational identity

(22)=1∧(33)=1\binom{2}{2} = 1 ∧ \binom{3}{3} = 1

holds by direct arithmetic evaluation.

Formalization Note: This corrects Lean-Workbook record lean_workbook_plus_29516, which omitted a compilable colon/type annotation and/or used a preamble of only Mathlib.Analysis.Complex.Basic.

Source: InternLM Lean-Workbook, record lean_workbook_plus_29516 (Apache-2.0).

Preamble
import Mathlib.Data.Nat.Choose.Basic
import Mathlib.Tactic.NormNum
Formal statement
theorem WorkbookCorrected.plus_29516 : ((Nat.choose 2 2) = 1) ∧ ((Nat.choose 3 3) = 1) := by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook; record lean_workbook_plus_29516; Apache-2.0; corrects Open node 80ae541f-f261-43f6-830c-0933f083b84f

View graph